net: bridge: provide shim definition for br_vlan_flags

br_vlan_replay() needs this, and we're preparing to move it to
br_switchdev.c, which will be compiled regardless of whether or not
CONFIG_BRIDGE_VLAN_FILTERING is enabled.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/bridge/br_private.h

@@ -1708,6 +1708,11 @@ static inline bool br_vlan_can_enter_range(const struct net_bridge_vlan *v_curr,
 	return true;
 }
 
+static inline u16 br_vlan_flags(const struct net_bridge_vlan *v, u16 pvid)
+{
+	return 0;
+}
+
 static inline int br_vlan_replay(struct net_device *br_dev,
 				 struct net_device *dev, const void *ctx,
 				 bool adding, struct notifier_block *nb,