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

Change-Id: I8a7c989540e8b62de7fd291f695adac849f4680c
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37843
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
diff --git a/src/mainboard/aopen/dxplplusu/acpi_tables.c b/src/mainboard/aopen/dxplplusu/acpi_tables.c
index cc6835b..70bfa27 100644
--- a/src/mainboard/aopen/dxplplusu/acpi_tables.c
+++ b/src/mainboard/aopen/dxplplusu/acpi_tables.c
@@ -20,6 +20,7 @@
 
 #include <arch/acpi.h>
 #include <device/pci.h>
+#include <device/pci_def.h>
 
 #define IOAPIC_ICH4		2
 #define IOAPIC_P64H2_BUS_B	3	/* IOAPIC 3 at 02:1c.0 */