net/mlx4: Add data structures to support N-Ports per VF

Adds the required data structures to support VFs with N (1 or 2)
ports instead of always using the number of physical ports.

Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>