net: dsa: move bridge device in dsa_port

Move the bridge_dev pointer from dsa_slave_priv to dsa_port so that DSA
drivers can access this information and remove the need to cache it.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/dsa.h b/include/net/dsa.h
index 6bd1f8b..924533f 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -146,6 +146,7 @@ struct dsa_port {
 	struct device_node	*dn;
 	unsigned int		ageing_time;
 	u8			stp_state;
+	struct net_device	*bridge_dev;
 };
 
 struct dsa_switch {