Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/net/dsa/mv88e6xxx/phy.c b/drivers/net/dsa/mv88e6xxx/phy.c
index 152a65d..252b5b3 100644
--- a/drivers/net/dsa/mv88e6xxx/phy.c
+++ b/drivers/net/dsa/mv88e6xxx/phy.c
@@ -1,14 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Marvell 88e6xxx Ethernet switch PHY and PPU support
  *
  * Copyright (c) 2008 Marvell Semiconductor
  *
  * Copyright (c) 2017 Andrew Lunn <andrew@lunn.ch>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
  */
 
 #include <linux/mdio.h>
@@ -141,7 +137,7 @@
 
 	chip = container_of(ugly, struct mv88e6xxx_chip, ppu_work);
 
-	mutex_lock(&chip->reg_lock);
+	mv88e6xxx_reg_lock(chip);
 
 	if (mutex_trylock(&chip->ppu_mutex)) {
 		if (mv88e6xxx_phy_ppu_enable(chip) == 0)
@@ -149,7 +145,7 @@
 		mutex_unlock(&chip->ppu_mutex);
 	}
 
-	mutex_unlock(&chip->reg_lock);
+	mv88e6xxx_reg_unlock(chip);
 }
 
 static void mv88e6xxx_phy_ppu_reenable_timer(struct timer_list *t)