staging: iio: add proper SPDX identifiers to remaining driver files

There are a number of IIO staging drivers that do not have a proper SPDX
identifier on it.  So fix that up and at the same time, remove the "free
form" license text, as that's pretty much impossible for any tool to
parse.

Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Michael Hennerich <Michael.Hennerich@analog.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/iio/accel/adis16203.c

+// SPDX-License-Identifier: GPL-2.0+
 /*
  * ADIS16203 Programmable 360 Degrees Inclinometer
  *
  * Copyright 2010 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
  */
 
 #include <linux/delay.h>

drivers/staging/iio/accel/adis16240.c

+// SPDX-License-Identifier: GPL-2.0+
 /*
  * ADIS16240 Programmable Impact Sensor and Recorder driver
  *
  * Copyright 2010 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
  */
 
 #include <linux/interrupt.h>

drivers/staging/iio/adc/ad7192.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * AD7190 AD7192 AD7193 AD7195 SPI ADC driver
  *
  * Copyright 2011-2015 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 
 #include <linux/interrupt.h>

drivers/staging/iio/adc/ad7192.h

+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * AD7190 AD7192 AD7195 SPI ADC driver
  *
  * Copyright 2011 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 #ifndef IIO_ADC_AD7192_H_
 #define IIO_ADC_AD7192_H_

drivers/staging/iio/adc/ad7280a.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * AD7280A Lithium Ion Battery Monitoring System
  *
  * Copyright 2011 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 
 #include <linux/crc8.h>

drivers/staging/iio/adc/ad7280a.h

+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * AD7280A Lithium Ion Battery Monitoring System
  *
  * Copyright 2011 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 
 #ifndef IIO_ADC_AD7280_H_

drivers/staging/iio/adc/ad7780.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * AD7170/AD7171 and AD7780/AD7781 SPI ADC driver
  *
  * Copyright 2011 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 
 #include <linux/interrupt.h>

drivers/staging/iio/adc/ad7816.c

+// SPDX-License-Identifier: GPL-2.0+
 /*
  * AD7816 digital temperature sensor driver supporting AD7816/7/8
  *
  * Copyright 2010 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
  */
 
 #include <linux/interrupt.h>

drivers/staging/iio/addac/adt7316-i2c.c

+// SPDX-License-Identifier: GPL-2.0+
 /*
  * I2C bus driver for ADT7316/7/8 ADT7516/7/9 digital temperature
  * sensor, ADC and DAC
  *
  * Copyright 2010 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
  */
 
 #include <linux/device.h>

drivers/staging/iio/addac/adt7316-spi.c

+// SPDX-License-Identifier: GPL-2.0+
 /*
  * API bus driver for ADT7316/7/8 ADT7516/7/9 digital temperature
  * sensor, ADC and DAC
  *
  * Copyright 2010 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
  */
 
 #include <linux/device.h>

drivers/staging/iio/addac/adt7316.c

+// SPDX-License-Identifier: GPL-2.0+
 /*
  * ADT7316 digital temperature sensor driver supporting ADT7316/7/8 ADT7516/7/9
  *
- *
  * Copyright 2010 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
  */
 
 #include <linux/interrupt.h>

drivers/staging/iio/addac/adt7316.h

+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * ADT7316 digital temperature sensor driver supporting ADT7316/7/8 ADT7516/7/9
  *
  * Copyright 2010 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
  */
 
 #ifndef _ADT7316_H_

drivers/staging/iio/cdc/ad7150.c

+// SPDX-License-Identifier: GPL-2.0+
 /*
  * AD7150 capacitive sensor driver supporting AD7150/1/6
  *
  * Copyright 2010-2011 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
  */
 
 #include <linux/interrupt.h>

drivers/staging/iio/cdc/ad7746.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * AD7746 capacitive sensor driver supporting AD7745, AD7746 and AD7747
  *
  * Copyright 2011 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 
 #include <linux/delay.h>

drivers/staging/iio/cdc/ad7746.h

+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * AD7746 capacitive sensor driver supporting AD7745, AD7746 and AD7747
  *
  * Copyright 2011 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 
 #ifndef IIO_CDC_AD7746_H_

drivers/staging/iio/frequency/ad9832.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * AD9832 SPI DDS driver
  *
  * Copyright 2011 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 
 #include <linux/device.h>

drivers/staging/iio/frequency/ad9832.h

+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * AD9832 SPI DDS driver
  *
  * Copyright 2011 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
  */
 #ifndef IIO_DDS_AD9832_H_
 #define IIO_DDS_AD9832_H_

drivers/staging/iio/frequency/ad9834.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * AD9833/AD9834/AD9837/AD9838 SPI DDS driver
  *
  * Copyright 2010-2011 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 
 #include <linux/clk.h>

drivers/staging/iio/frequency/ad9834.h

+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * AD9833/AD9834/AD9837/AD9838 SPI DDS driver
  *
  * Copyright 2010-2011 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 #ifndef IIO_DDS_AD9834_H_
 #define IIO_DDS_AD9834_H_

drivers/staging/iio/frequency/dds.h

+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * dds.h - sysfs attributes associated with DDS devices
  *
  * Copyright (c) 2010 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
  */
 #ifndef IIO_DDS_H_
 #define IIO_DDS_H_

drivers/staging/iio/impedance-analyzer/ad5933.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * AD5933 AD5934 Impedance Converter, Network Analyzer
  *
  * Copyright 2011 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 
 #include <linux/interrupt.h>

drivers/staging/iio/meter/ade7854-i2c.c

+// SPDX-License-Identifier: GPL-2.0+
 /*
  * ADE7854/58/68/78 Polyphase Multifunction Energy Metering IC Driver (I2C Bus)
  *
  * Copyright 2010 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
  */
 
 #include <linux/device.h>

drivers/staging/iio/meter/ade7854-spi.c

+// SPDX-License-Identifier: GPL-2.0+
 /*
  * ADE7854/58/68/78 Polyphase Multifunction Energy Metering IC Driver (SPI Bus)
  *
  * Copyright 2010 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
  */
 
 #include <linux/device.h>

drivers/staging/iio/meter/ade7854.c

+// SPDX-License-Identifier: GPL-2.0+
 /*
  * ADE7854/58/68/78 Polyphase Multifunction Energy Metering IC Driver
  *
  * Copyright 2010 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
  */
 
 #include <linux/interrupt.h>

drivers/staging/iio/resolver/ad2s1210.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * ad2s1210.c support for the ADI Resolver to Digital Converters: AD2S1210
  *
  * Copyright (c) 2010-2010 Analog Devices Inc.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
  */
 #include <linux/types.h>
 #include <linux/mutex.h>