MIPS: Add CPU support for Loongson1B

Loongson 1B is a 32-bit SoC designed by Institute of Computing Technology
(ICT) and the Chinese Academy of Sciences (CAS), which implements the
MIPS32 release 2 instruction set.

[ralf@linux-mips.org: But which is not strictly a MIPS32 compliant device
which also is why it identifies itself with the Legacy Vendor ID in the
PrID register.  When applying the patch I shoveled some code around to
keep things in alphabetical order and avoid forward declarations.]

Signed-off-by: Kelvin Cheung <keguang.zhang@gmail.com>
Cc: To: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: wuzhangjin@gmail.com
Cc: zhzhl555@gmail.com
Cc: Kelvin Cheung <keguang.zhang@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/3976/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
index 95e40c1..f21b7c0 100644
--- a/arch/mips/include/asm/cpu.h
+++ b/arch/mips/include/asm/cpu.h
@@ -197,6 +197,7 @@
 #define PRID_REV_VR4181A	0x0070	/* Same as VR4122 */
 #define PRID_REV_VR4130		0x0080
 #define PRID_REV_34K_V1_0_2	0x0022
+#define PRID_REV_LOONGSON1B	0x0020
 #define PRID_REV_LOONGSON2E	0x0002
 #define PRID_REV_LOONGSON2F	0x0003
 
@@ -261,7 +262,7 @@
 	 */
 	CPU_4KC, CPU_4KEC, CPU_4KSC, CPU_24K, CPU_34K, CPU_1004K, CPU_74K,
 	CPU_ALCHEMY, CPU_PR4450, CPU_BMIPS32, CPU_BMIPS3300, CPU_BMIPS4350,
-	CPU_BMIPS4380, CPU_BMIPS5000, CPU_JZRISC, CPU_M14KC,
+	CPU_BMIPS4380, CPU_BMIPS5000, CPU_JZRISC, CPU_LOONGSON1, CPU_M14KC,
 
 	/*
 	 * MIPS64 class processors
diff --git a/arch/mips/include/asm/module.h b/arch/mips/include/asm/module.h
index 5300080..7531ecd 100644
--- a/arch/mips/include/asm/module.h
+++ b/arch/mips/include/asm/module.h
@@ -117,6 +117,8 @@
 #define MODULE_PROC_FAMILY "RM9000 "
 #elif defined CONFIG_CPU_SB1
 #define MODULE_PROC_FAMILY "SB1 "
+#elif defined CONFIG_CPU_LOONGSON1
+#define MODULE_PROC_FAMILY "LOONGSON1 "
 #elif defined CONFIG_CPU_LOONGSON2
 #define MODULE_PROC_FAMILY "LOONGSON2 "
 #elif defined CONFIG_CPU_CAVIUM_OCTEON