Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/linux/of_mdio.h b/include/linux/of_mdio.h
index f5db93b..99cefe6 100644
--- a/include/linux/of_mdio.h
+++ b/include/linux/of_mdio.h
@@ -1,9 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * OF helpers for the MDIO (Ethernet PHY) API
  *
  * Copyright (c) 2009 Secret Lab Technologies, Ltd.
- *
- * This file is released under the GPLv2
  */
 
 #ifndef __LINUX_OF_MDIO_H