treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 74

Based on 1 normalized pattern(s):

  you may copy modify and redistribute this file under the terms of
  the gnu general public license version 2 or any later version at
  your convenience

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>