Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c
index d7216c9..a36fd05 100644
--- a/arch/powerpc/kernel/idle.c
+++ b/arch/powerpc/kernel/idle.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Idle daemon for PowerPC.  Idle daemon will handle any action
  * that needs to be taken when the system becomes idle.
@@ -12,11 +13,6 @@
  *    Copyright (c) 2003 Dave Engebretsen <engebret@us.ibm.com>
  *
  * 32-bit and 64-bit versions merged by Paul Mackerras <paulus@samba.org>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
  */
 
 #include <linux/sched.h>