net/mlx4_en: Re-arrange ndo_set_rx_mode related code

Currently, mlx4_en_do_set_multicast serves as the ndo_set_rx_mode entry for mlx4_en,
doing all related work. Split it to few calls, one per required functionality
(e.g multicast, promiscuous, etc) and rename some structures and calls
to use rx_mode notation instead of multicast.

Signed-off-by: Yan Burman <yanb@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>