nb/intel/i440bx: Remove unnecessary __SIMPLE_DEVICE__

This file is only included in romstage.

Change-Id: Ib9ee6e88e7a6ef81034de608232a05e92a16d5f4
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36773
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>

src/northbridge/intel/i440bx/memmap.c

@@ -13,8 +13,6 @@
  * GNU General Public License for more details.
  */
 
-#define __SIMPLE_DEVICE__
-
 #include <arch/romstage.h>
 #include <device/pci_ops.h>
 #include <cbmem.h>