soc/intel: Rename some SMM support functions

Rename southbridge_smm_X to smm_southbridge_X.
Rename most southcluster_smm_X to smm_southbridge_X.

Change-Id: I4f6f9207ba32cf51d75b9ca9230e38310a33a311
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34856
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/cpu/intel/haswell/haswell_init.c

@@ -24,6 +24,7 @@
 #include <cpu/x86/mp.h>
 #include <cpu/x86/lapic.h>
 #include <cpu/intel/microcode.h>
+#include <cpu/intel/smm_reloc.h>
 #include <cpu/intel/speedstep.h>
 #include <cpu/intel/turbo.h>
 #include <cpu/x86/cache.h>
@@ -761,7 +762,7 @@ static void post_mp_init(void)
 {
 	/* Now that all APs have been relocated as well as the BSP let SMIs
 	 * start flowing. */
-	southbridge_smm_enable_smi();
+	smm_southbridge_enable_smi();
 
 	/* Lock down the SMRAM space. */
 	smm_lock();