amd/common: Add the macro definition for patch level MSR

This MSR is used for detecting if the micro code is applied
successfully.

Change-Id: I060eb1a31f3358341ac0d5b9105e710c351f2ce8
Signed-off-by: Zheng Bao <zheng.bao@amd.com>
Signed-off-by: Zheng Bao <fishbaozi@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/42212
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/include/cpu/amd/msr.h b/src/include/cpu/amd/msr.h
index d23a4bd..606ea23 100644
--- a/src/include/cpu/amd/msr.h
+++ b/src/include/cpu/amd/msr.h
@@ -73,6 +73,7 @@
 #define LS_CFG2_MSR			0xC001102D
 #define IBS_OP_DATA3_MSR		0xC0011037
 
+#define MSR_PATCH_LEVEL			0x0000008B
 #define CORE_PERF_BOOST_CTRL		0x15c
 
 #endif /* CPU_AMD_MSR_H */