Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/mips/loongson64/common/env.c b/arch/mips/loongson64/common/env.c
index 8f68ee0..09d5cf4 100644
--- a/arch/mips/loongson64/common/env.c
+++ b/arch/mips/loongson64/common/env.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Based on Ocelot Linux port, which is
  * Copyright 2001 MontaVista Software Inc.
@@ -11,11 +12,6 @@
  *
  * Copyright (C) 2009 Lemote Inc.
  * Author: Wu Zhangjin, wuzhangjin@gmail.com
- *
- * 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/export.h>
 #include <asm/bootinfo.h>
@@ -197,7 +193,8 @@
 			cpu_clock_freq = 797000000;
 			break;
 		case PRID_REV_LOONGSON3A_R1:
-		case PRID_REV_LOONGSON3A_R2:
+		case PRID_REV_LOONGSON3A_R2_0:
+		case PRID_REV_LOONGSON3A_R2_1:
 		case PRID_REV_LOONGSON3A_R3_0:
 		case PRID_REV_LOONGSON3A_R3_1:
 			cpu_clock_freq = 900000000;