Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/clocksource/timer-stm32.c b/drivers/clocksource/timer-stm32.c
index 2717f88..c9a753f 100644
--- a/drivers/clocksource/timer-stm32.c
+++ b/drivers/clocksource/timer-stm32.c
@@ -1,7 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) Maxime Coquelin 2015
  * Author:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
- * License terms:  GNU General Public License (GPL), version 2
  *
  * Inspired by time-efm32.c from Uwe Kleine-Koenig
  */