src: Get rid of duplicated includes

Change-Id: I252a1cd77bf647477edb7dddadb7e527de872439
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/29582
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>

src/commonlib/storage/mmc.c

@@ -21,7 +21,6 @@
 
 #include <commonlib/storage.h>
 #include <delay.h>
-#include "sd_mmc.h"
 #include "mmc.h"
 #include "sd_mmc.h"
 #include "storage.h"