vlan: multiqueue vlan device

vlan devices are currently not multi-queue capable.

We can do that with a new rtnl_link_ops method,
get_tx_queues(), called from rtnl_create_link()

This new method gets num_tx_queues/real_num_tx_queues
from real device.

register_vlan_device() is also handled.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index 3c1895e..b630196 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -70,6 +70,9 @@
 	size_t			(*get_xstats_size)(const struct net_device *dev);
 	int			(*fill_xstats)(struct sk_buff *skb,
 					       const struct net_device *dev);
+	int			(*get_tx_queues)(struct net *net, struct nlattr *tb[],
+						 unsigned int *tx_queues,
+						 unsigned int *real_tx_queues);
 };
 
 extern int	__rtnl_link_register(struct rtnl_link_ops *ops);