Drop ROMCC code and header guards

Change-Id: I730f80afd8aad250f26534435aec24bea75a849c
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37334
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>

src/console/post.c

@@ -24,8 +24,6 @@
 
 /* Write POST information */
 
-/* someday romcc will be gone. */
-#ifndef __ROMCC__
 /* Some mainboards have very nice features beyond just a simple display.
  * They can override this function.
  */
@@ -33,11 +31,6 @@ void __weak mainboard_post(uint8_t value)
 {
 }
 
-#else
-/* This just keeps the number of #ifs to a minimum */
-#define mainboard_post(x)
-#endif
-
 #if CONFIG(CMOS_POST)
 
 DECLARE_SPIN_LOCK(cmos_post_lock)