treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 149

Based on 1 normalized pattern(s):

  licensed under the gpl 2 or later

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 82 file(s).

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