northbridge: Add missing include <device/pci_def.h>

Change-Id: Ib63835d2407bbabbd78b43927f7fbd407ca06a08
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37841
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/northbridge/intel/gm45/acpi.c b/src/northbridge/intel/gm45/acpi.c
index ef152db..82b6221 100644
--- a/src/northbridge/intel/gm45/acpi.c
+++ b/src/northbridge/intel/gm45/acpi.c
@@ -20,6 +20,7 @@
 #include <arch/acpigen.h>
 #include <device/device.h>
 #include <device/pci.h>
+#include <device/pci_def.h>
 #include <device/pci_ops.h>
 
 #include "gm45.h"