treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 249 Based on 1 normalized pattern(s): as all part of the linux kernel this file is gpl extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de>