iio:bmi160: add SPDX identifiers

Add SPDX identifiers (GPL 2) for the BMI160 driver. bmi160.h had an
identifier, but the other files did not.
Signed-off-by: Martin Kelly <martin@martingkelly.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/bmi160/bmi160_core.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * BMI160 - Bosch IMU (accel, gyro plus external magnetometer)
  *
  * Copyright (c) 2016, Intel Corporation.
  *
- * This file is subject to the terms and conditions of version 2 of
- * the GNU General Public License.  See the file COPYING in the main
- * directory of this archive for more details.
- *
  * IIO core driver for BMI160, with support for I2C/SPI busses
  *
  * TODO: magnetometer, interrupts, hardware FIFO

drivers/iio/imu/bmi160/bmi160_i2c.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * BMI160 - Bosch IMU, I2C bits
  *
  * Copyright (c) 2016, Intel Corporation.
  *
- * This file is subject to the terms and conditions of version 2 of
- * the GNU General Public License.  See the file COPYING in the main
- * directory of this archive for more details.
- *
  * 7-bit I2C slave address is:
  *      - 0x68 if SDO is pulled to GND
  *      - 0x69 if SDO is pulled to VDDIO

drivers/iio/imu/bmi160/bmi160_spi.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * BMI160 - Bosch IMU, SPI bits
  *
  * Copyright (c) 2016, Intel Corporation.
  *
- * This file is subject to the terms and conditions of version 2 of
- * the GNU General Public License.  See the file COPYING in the main
- * directory of this archive for more details.
  */
 #include <linux/acpi.h>
 #include <linux/module.h>