net/mlx5e: Fix VXLAN configuration restore after function reload

When detaching netdev, remove vxlan port configuration using
udp_tunnel_drop_rx_info. During function reload, configuration will be
restored using udp_tunnel_get_rx_info. This ensures sync between
firmware and driver. Use udp_tunnel_get_rx_info even if its physical
interface is down.

Fixes: 4383cfcc ("net/mlx5: Add devlink reload")
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>