cpu/amd: Use common AMD's MSR

Phase 1. Due to the size of the effort, this CL is broken into several
phases.

Change-Id: I0236e0960cd1e79558ea50c814e1de2830aa0550
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/29065
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Richard Spiegel <richard.spiegel@silverbackltd.com>
diff --git a/src/cpu/amd/agesa/family15tn/udelay.c b/src/cpu/amd/agesa/family15tn/udelay.c
index 3d40fc3..7ff4c5c 100644
--- a/src/cpu/amd/agesa/family15tn/udelay.c
+++ b/src/cpu/amd/agesa/family15tn/udelay.c
@@ -21,6 +21,7 @@
  */
 
 #include <cpu/x86/msr.h>
+#include <cpu/amd/msr.h>
 #include <cpu/x86/tsc.h>
 #include <delay.h>
 #include <stdint.h>
@@ -36,11 +37,11 @@
 	tsc_start = rdtscll();
 
 	/* Get the P-state. This determines which MSR to read */
-	msr = rdmsr(0xc0010063);
+	msr = rdmsr(PS_STS_REG);
 	pstate_idx = msr.lo & 0x07;
 
 	/* Get FID and VID for current P-State */
-	msr = rdmsr(0xc0010064 + pstate_idx);
+	msr = rdmsr(PSTATE_0_MSR + pstate_idx);
 
 	/* Extract the FID and VID values */
 	fid = msr.lo & 0x3f;