When LAG is active, port up/down events should be triggered
by tracking the LAG master, and not one of the two slave
netdevs.

In the same manner, ib_query_port() should return the details
of the LAG master.
Signed-off-by: NAviv Heller <avivh@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>