arch/x86: Drop spurious arch/stages.h includes

Change-Id: I3b9217a7d9a6d98a9c5e8b69fe64c260b537bb64
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/30388
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/arch/x86/boot.c

@@ -13,7 +13,6 @@
 
 #include <commonlib/helpers.h>
 #include <console/console.h>
-#include <arch/stages.h>
 #include <program_loading.h>
 #include <ip_checksum.h>
 #include <string.h>