Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/pwm/pwm-ab8500.c b/drivers/pwm/pwm-ab8500.c
index f393992..fdf3964 100644
--- a/drivers/pwm/pwm-ab8500.c
+++ b/drivers/pwm/pwm-ab8500.c
@@ -1,8 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) ST-Ericsson SA 2010
  *
  * Author: Arun R Murthy <arun.murthy@stericsson.com>
- * License terms: GNU General Public License (GPL) version 2
  */
 #include <linux/err.h>
 #include <linux/platform_device.h>