Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/kernel/power/suspend_test.c b/kernel/power/suspend_test.c
index 6a897e8..60564b5 100644
--- a/kernel/power/suspend_test.c
+++ b/kernel/power/suspend_test.c
@@ -1,9 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * kernel/power/suspend_test.c - Suspend to RAM and standby test facility.
  *
  * Copyright (c) 2009 Pavel Machek <pavel@ucw.cz>
- *
- * This file is released under the GPLv2.
  */
 
 #include <linux/init.h>