drivers/pc80/rtc: Remove stub for cmos_post_init()

We only have a single call-site for this.

Change-Id: Ia05a762691351b37cc59b39222fec737b29e913c
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38181
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/lib/bootblock.c

@@ -57,7 +57,9 @@ static void bootblock_main_with_timestamp(uint64_t base_timestamp,
 	bootblock_mainboard_early_init();
 
 	sanitize_cmos();
-	cmos_post_init();
+
+	if (CONFIG(CMOS_POST))
+		cmos_post_init();
 
 	if (CONFIG(BOOTBLOCK_CONSOLE)) {
 		console_init();