WorkStruct: make allyesconfig

Fix up for make allyesconfig.

Signed-Off-By: David Howells <dhowells@redhat.com>
diff --git a/drivers/net/wireless/bcm43xx/bcm43xx.h b/drivers/net/wireless/bcm43xx/bcm43xx.h
index d6a8bf0..fbc0c08 100644
--- a/drivers/net/wireless/bcm43xx/bcm43xx.h
+++ b/drivers/net/wireless/bcm43xx/bcm43xx.h
@@ -787,7 +787,7 @@
 	struct tasklet_struct isr_tasklet;
 
 	/* Periodic tasks */
-	struct work_struct periodic_work;
+	struct delayed_work periodic_work;
 	unsigned int periodic_state;
 
 	struct work_struct restart_work;