uwb: lock rc->rsvs_lock with spin_lock_bh()

rc->rsvs_lock may be taken in a timer so lock it with spin_lock_bh().

Signed-off-by: David Vrabel <david.vrabel@csr.com>
diff --git a/drivers/uwb/drp.c b/drivers/uwb/drp.c
index 2b4f940..4f5ca99 100644
--- a/drivers/uwb/drp.c
+++ b/drivers/uwb/drp.c
@@ -66,14 +66,14 @@
 	} else
 		dev_err(&rc->uwb_dev.dev, "SET-DRP-IE: timeout\n");
 
-	spin_lock(&rc->rsvs_lock);
+	spin_lock_bh(&rc->rsvs_lock);
 	if (rc->set_drp_ie_pending > 1) {
 		rc->set_drp_ie_pending = 0;
 		uwb_rsv_queue_update(rc);	
 	} else {
 		rc->set_drp_ie_pending = 0;	
 	}
-	spin_unlock(&rc->rsvs_lock);
+	spin_unlock_bh(&rc->rsvs_lock);
 }
 
 /**