Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/mailbox/platform_mhu.c b/drivers/mailbox/platform_mhu.c
index e13201a..b6e3495 100644
--- a/drivers/mailbox/platform_mhu.c
+++ b/drivers/mailbox/platform_mhu.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2016 BayLibre SAS.
  * Author: Neil Armstrong <narmstrong@baylibre.com>
@@ -5,15 +6,6 @@
  * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd.
  * Copyright (C) 2015 Linaro Ltd.
  * Author: Jassi Brar <jaswinder.singh@linaro.org>
- *
- * 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, version 2 of the License.
- *
- * This program is distributed in the hope that 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 <linux/interrupt.h>
@@ -163,7 +155,7 @@
 
 	platform_set_drvdata(pdev, mhu);
 
-	err = mbox_controller_register(&mhu->mbox);
+	err = devm_mbox_controller_register(dev, &mhu->mbox);
 	if (err) {
 		dev_err(dev, "Failed to register mailboxes %d\n", err);
 		return err;
@@ -173,15 +165,6 @@
 	return 0;
 }
 
-static int platform_mhu_remove(struct platform_device *pdev)
-{
-	struct platform_mhu *mhu = platform_get_drvdata(pdev);
-
-	mbox_controller_unregister(&mhu->mbox);
-
-	return 0;
-}
-
 static const struct of_device_id platform_mhu_dt_ids[] = {
 	{ .compatible = "amlogic,meson-gxbb-mhu", },
 	{ /* sentinel */ },
@@ -190,7 +173,6 @@
 
 static struct platform_driver platform_mhu_driver = {
 	.probe	= platform_mhu_probe,
-	.remove	= platform_mhu_remove,
 	.driver = {
 		.name = "platform-mhu",
 		.of_match_table	= platform_mhu_dt_ids,