net/mlx5: Move devlink port from mlx5e priv to mlx5e resources

We re-use the native NIC port net device instance for the Uplink
representor, and the devlink port.
When changing profiles we reset the mlx5e priv but we should still
use the devlink port so move it to mlx5e resources.

Signed-off-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>