i2c: mux: pca954x: Convert license to SPDX identifier

Use a shorter SPDX identifier instead of pasting the whole license.

While here, replace duplicating PCA954x with PCA984x.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/muxes/i2c-mux-pca954x.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * I2C multiplexer
  *
  * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
  * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
  *
- * This module supports the PCA954x and PCA954x series of I2C multiplexer/switch
+ * This module supports the PCA954x and PCA984x series of I2C multiplexer/switch
  * chips made by NXP Semiconductors.
  * This includes the:
  *	 PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547,
@@ -29,10 +30,6 @@
  *	i2c-virtual_cb.c from Brian Kuschak <bkuschak@yahoo.com>
  * and
  *	pca9540.c from Jean Delvare <jdelvare@suse.de>.
- *
- * This file is licensed under the terms of the GNU General Public
- * License version 2. This program is licensed "as is" without any
- * warranty of any kind, whether express or implied.
  */
 
 #include <linux/device.h>