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>
diff --git a/src/southbridge/intel/common/smi.c b/src/southbridge/intel/common/smi.c
index dafb732..1348174 100644
--- a/src/southbridge/intel/common/smi.c
+++ b/src/southbridge/intel/common/smi.c
@@ -34,7 +34,7 @@
 	return lpc_get_pmbase();
 }
 
-void southbridge_smm_init(void)
+void smm_southbridge_enable_smi(void)
 {
 	u32 smi_en;
 	u16 pm1_en;
@@ -123,7 +123,7 @@
 	);
 }
 
-void southbridge_smm_clear_state(void)
+void smm_southbridge_clear_state(void)
 {
 	u32 smi_en;