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/soc/intel/apollolake/cpu.c

@@ -31,6 +31,7 @@
 #include <cpu/x86/mtrr.h>
 #include <cpu/x86/smm.h>
 #include <cpu/intel/em64t100_save_state.h>
+#include <cpu/intel/smm_reloc.h>
 #include <device/device.h>
 #include <device/pci.h>
 #include <fsp/api.h>
@@ -39,7 +40,6 @@
 #include <intelblocks/mp_init.h>
 #include <intelblocks/msr.h>
 #include <intelblocks/sgx.h>
-#include <intelblocks/smm.h>
 #include <reg_script.h>
 #include <romstage_handoff.h>
 #include <soc/cpu.h>