src: Remove unused include device/pnp_def.h

Change-Id: Ibb7ce42588510dc5ffb04c950c4c8c64e9a2fa37
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/31238
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>

src/northbridge/intel/gm45/raminit.c

@@ -19,7 +19,6 @@
 #include <arch/cpu.h>
 #include <arch/io.h>
 #include <device/pci_def.h>
-#include <device/pnp_def.h>
 #include <device/device.h>
 #include <spd.h>
 #include <console/console.h>