Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/x86/boot/apm.c b/arch/x86/boot/apm.c
index ee27483..b72fc10 100644
--- a/arch/x86/boot/apm.c
+++ b/arch/x86/boot/apm.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* -*- linux-c -*- ------------------------------------------------------- *
  *
  *   Copyright (C) 1991, 1992 Linus Torvalds
@@ -7,9 +8,6 @@
  *   Original APM BIOS checking by Stephen Rothwell, May 1994
  *   (sfr@canb.auug.org.au)
  *
- *   This file is part of the Linux kernel, and is made available under
- *   the terms of the GNU General Public License version 2.
- *
  * ----------------------------------------------------------------------- */
 
 /*