treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 440

Based on 1 normalized pattern(s):

  this software is available under the terms of the gnu general public
  license gpl version 2 available from the file copying in the main
  directory of this source tree

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 35 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.411886531@linutronix.de


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