drivers/pc80/rtc: Clean up some headers

Change-Id: I5b3f1da6581dd80264aaa9618227ac64e1966e8d
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38180
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/arch/x86/bootblock_normal.c

@@ -12,7 +12,7 @@
  */
 
 #include <cbfs.h>
-#include <pc80/mc146818rtc.h>
+#include <fallback.h>
 #include <program_loading.h>
 #include <stddef.h>
 #include <string.h>