net/mlx5: E-Switch, Consider SF ports of host PF

Query SF vports count and base id of host PF from the firmware.

Account these ports in the total port calculation whenever it is non
zero.

Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Vu Pham <vuhuong@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>