Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/rtc/rtc-sirfsoc.c b/drivers/rtc/rtc-sirfsoc.c
index 2a9e151..c759c55 100644
--- a/drivers/rtc/rtc-sirfsoc.c
+++ b/drivers/rtc/rtc-sirfsoc.c
@@ -1,9 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * SiRFSoC Real Time Clock interface for Linux
  *
  * Copyright (c) 2013 Cambridge Silicon Radio Limited, a CSR plc group company.
- *
- * Licensed under GPLv2 or later.
  */
 
 #include <linux/module.h>
@@ -279,7 +278,7 @@
 	{},
 };
 
-const struct regmap_config sysrtc_regmap_config = {
+static const struct regmap_config sysrtc_regmap_config = {
 	.reg_bits = 32,
 	.val_bits = 32,
 	.fast_io = true,