Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/ide/icside.c b/drivers/ide/icside.c
index 80e933b..329c7e4 100644
--- a/drivers/ide/icside.c
+++ b/drivers/ide/icside.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 1996-2004 Russell King.
  *