drivers/pc80/rtc: Reorganize prototypes

Change-Id: Idea18f437c31ebe83dd61a185e614106a1f8f976
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38199
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/drivers/elog/elog.c

@@ -7,14 +7,12 @@
 #include <bootstate.h>
 #include <cbmem.h>
 #include <console/console.h>
-#if CONFIG(ARCH_X86)
-#include <pc80/mc146818rtc.h>
-#endif
 #include <bcd.h>
 #include <boot_device.h>
 #include <commonlib/region.h>
 #include <fmap.h>
 #include <lib.h>
+#include <post.h>
 #include <rtc.h>
 #include <smbios.h>
 #include <stdint.h>