treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 350

Based on 1 normalized pattern(s):

  this program may be used under the terms of version 2 of the gnu
  general public license

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 1 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000437.975825562@linutronix.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/powerpc/boot/wrapper

 #!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-only
 
 # Copyright (C) 2006 Paul Mackerras, IBM Corporation <paulus@samba.org>
-# This program may be used under the terms of version 2 of the GNU
-# General Public License.
 
 # This script takes a kernel binary and optionally an initrd image
 # and/or a device-tree blob, and creates a bootable zImage for a