cpu/x86: Move some SMM function declarations

Change-Id: I9a4e57f8fd032f2824eab0e5b59d635710e3e24b
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34822
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/southbridge/intel/fsp_rangeley/lpc.c

@@ -28,6 +28,7 @@
 #include <arch/ioapic.h>
 #include <arch/acpi.h>
 #include <arch/cpu.h>
+#include <cpu/x86/smm.h>
 #include <elog.h>
 #include <string.h>
 #include <cbmem.h>