iio: mma8452: replace license description with SPDX specifier

This replaces the custom license information text with the appropriate
SPDX identifier. While the information here stays the same, it is easier
to read.

Signed-off-by: Martin Kepplinger <martink@posteo.de>
Acked-by: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Acked-by: Harinath Nampally <harinath922@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/iio/accel/mma8452.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * mma8452.c - Support for following Freescale / NXP 3-axis accelerometers:
  *
@@ -13,9 +14,6 @@
  * Copyright 2015 Martin Kepplinger <martink@posteo.de>
  * Copyright 2014 Peter Meerwald <pmeerw@pmeerw.net>
  *
- * 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.
  *
  * TODO: orientation events
  */