Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/caif/cfmuxl.c b/net/caif/cfmuxl.c
index 510aa5a..4172b0d 100644
--- a/net/caif/cfmuxl.c
+++ b/net/caif/cfmuxl.c
@@ -1,7 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) ST-Ericsson AB 2010
  * Author:	Sjur Brendeland
- * License terms: GNU General Public License (GPL) version 2
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__