Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/clk/microchip/clk-pic32mzda.c b/drivers/clk/microchip/clk-pic32mzda.c
index 9f73477..b72c76f 100644
--- a/drivers/clk/microchip/clk-pic32mzda.c
+++ b/drivers/clk/microchip/clk-pic32mzda.c
@@ -1,20 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Purna Chandra Mandal,<purna.mandal@microchip.com>
  * Copyright (C) 2015 Microchip Technology Inc.  All rights reserved.
- *
- * This program is free software; you can distribute it and/or modify it
- * under the terms of the GNU General Public License (Version 2) as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * for more details.
  */
 #include <dt-bindings/clock/microchip,pic32-clock.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
 #include <linux/clkdev.h>
+#include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/of_platform.h>