treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 420

Based on 1 normalized pattern(s):

  this code 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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 6 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190113.627158185@linutronix.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>