net/mlx5: Use correct vport when restoring GUIDs

Prior to enabling EC VF functionality the vport number and function ID
were always the same. That's not the case now. Use the correct vport
number to modify the HCA vport context.

Signed-off-by: Daniel Jurgens <danielj@nvidia.com>
Reviewed-by: William Tu <witu@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>