mlx4: Extanding port_mask functionality

Port mask now has additional state.
Port can be set as "none". In this case neither the mlx4_en or mlx4_ib
drivers take ownership of the port.
In multifunction mode there is an option to set the vfs as single ported devices.
(in single function mode, both physical ports belong to same function)

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>