cpu/x86/smm: Use common APMC logging

Unify the debug messages on raised SMIs.

Change-Id: I34eeb41d929bfb18730ac821a63bde95ef9a0b3e
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49248
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/include/cpu/x86/smm.h

@@ -33,6 +33,7 @@
 
 /* Send cmd to APM_CNT with HAVE_SMI_HANDLER checking. */
 int apm_control(u8 cmd);
+u8 apm_get_apmc(void);
 
 void io_trap_handler(int smif);
 int southbridge_io_trap_handler(int smif);