[BRIDGE]: set features based on enslaved devices

Make features of the bridge pseudo-device be a subset of the underlying
devices.  Motivated by Xen and others who use bridging to do failover.

Signed-off-by: Catalin BOIE <catab at umrella.ro>
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 54d63f13..bdf95a7 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -174,6 +174,7 @@
 extern int br_del_if(struct net_bridge *br,
 	      struct net_device *dev);
 extern int br_min_mtu(const struct net_bridge *br);
+extern void br_features_recompute(struct net_bridge *br);
 
 /* br_input.c */
 extern int br_handle_frame_finish(struct sk_buff *skb);