smmstore: make smmstore's SMM handler code follow everything else

Instead of SMMSTORE_APM_CNT use APM_CNT_SMMSTORE and define it in
cpu/x86/smm.h

Change-Id: Iabc0c9662284ed3ac2933001e64524011a5bf420
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/30023
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/include/cpu/x86/smm.h

@@ -473,6 +473,7 @@ typedef struct {
 #define APM_CNT_GNVS_UPDATE	0xea
 #define APM_CNT_FINALIZE	0xcb
 #define APM_CNT_LEGACY		0xcc
+#define APM_CNT_SMMSTORE	0xed
 #define APM_CNT_ELOG_GSMI	0xef
 #define APM_STS		0xb3
 

src/include/smmstore.h

@@ -19,8 +19,6 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#define SMMSTORE_APM_CNT 0xed
-
 #define SMMSTORE_RET_SUCCESS 0
 #define SMMSTORE_RET_FAILURE 1
 #define SMMSTORE_RET_UNSUPPORTED 2