northbridge/amd: Use DEVICE_NOOP macro over dummy symbol

Change-Id: I3fdd2a9f981592112998d74ce4cfe4850d8fab31
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/7288
Tested-by: build bot (Jenkins)
Reviewed-by: Bruce Griffith <Bruce.Griffith@se-eng.com>
diff --git a/src/northbridge/amd/agesa/00730F01/northbridge.c b/src/northbridge/amd/agesa/00730F01/northbridge.c
index 2689569..03433af 100644
--- a/src/northbridge/amd/agesa/00730F01/northbridge.c
+++ b/src/northbridge/amd/agesa/00730F01/northbridge.c
@@ -1081,10 +1081,6 @@
 	initialize_cpus(dev->link_list);
 }
 
-static void cpu_bus_noop(device_t dev)
-{
-}
-
 static void cpu_bus_read_resources(device_t dev)
 {
 #if CONFIG_MMCONF_SUPPORT
@@ -1108,7 +1104,7 @@
 static struct device_operations cpu_bus_ops = {
 	.read_resources	  = cpu_bus_read_resources,
 	.set_resources	  = cpu_bus_set_resources,
-	.enable_resources = cpu_bus_noop,
+	.enable_resources = DEVICE_NOOP,
 	.init		  = cpu_bus_init,
 	.scan_bus	  = cpu_bus_scan,
 };