cpu/mtrr.h: Fix macro names for MTRR registers

We use UNDERSCORE_CASE. For the MTRR macros that refer to an MSR,
we also remove the _MSR suffix, as they are, by definition, MSRs.

Change-Id: Id4483a75d62cf1b478a9105ee98a8f55140ce0ef
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/11761
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
diff --git a/src/cpu/amd/smm/smm_init.c b/src/cpu/amd/smm/smm_init.c
index 2e9a4c9..e13f24f 100644
--- a/src/cpu/amd/smm/smm_init.c
+++ b/src/cpu/amd/smm/smm_init.c
@@ -39,7 +39,7 @@
 
 	/* Back up MSRs for later restore */
 	syscfg_orig = rdmsr(SYSCFG_MSR);
-	mtrr_aseg_orig = rdmsr(MTRRfix16K_A0000_MSR);
+	mtrr_aseg_orig = rdmsr(MTRR_FIX_16K_A0000);
 
 	/* MTRR changes don't like an enabled cache */
 	disable_cache();
@@ -57,7 +57,7 @@
 	/* set DRAM access to 0xa0000 */
 	msr.lo = 0x18181818;
 	msr.hi = 0x18181818;
-	wrmsr(MTRRfix16K_A0000_MSR, msr);
+	wrmsr(MTRR_FIX_16K_A0000, msr);
 
 	/* enable the extended features */
 	msr = syscfg_orig;
@@ -73,7 +73,7 @@
 
 	/* Restore SYSCFG and MTRR */
 	wrmsr(SYSCFG_MSR, syscfg_orig);
-	wrmsr(MTRRfix16K_A0000_MSR, mtrr_aseg_orig);
+	wrmsr(MTRR_FIX_16K_A0000, mtrr_aseg_orig);
 	enable_cache();
 
 	/* CPU MSR are set in CPU init */