Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/mips/lantiq/clk.h b/arch/mips/lantiq/clk.h
index e806e04..f135e30 100644
--- a/arch/mips/lantiq/clk.h
+++ b/arch/mips/lantiq/clk.h
@@ -1,7 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
- *  This program is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License version 2 as published
- *  by the Free Software Foundation.
  *
  * Copyright (C) 2010 John Crispin <john@phrozen.org>
  */