nb/intel/i440bx: Get rid of device_t

Use of device_t has been abandoned in ramstage.

Change-Id: I69c8b95ff1937c0b08147d9e26a3118c58129cf5
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/26197
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>

src/northbridge/intel/i440bx/northbridge.c

@@ -34,7 +34,7 @@ static const struct pci_driver northbridge_driver __pci_driver = {
 
 static void i440bx_domain_set_resources(struct device *dev)
 {
-	device_t mc_dev;
+	struct device *mc_dev;
 	uint32_t pci_tolm;
 
 	pci_tolm = find_pci_tolm(dev->link_list);