net/mlx5: E-Switch, Prepare for vport enable/disable refactor

Rename esw_apply_vport_config() to esw_vport_setup(), and add new
helper function esw_vport_cleanup() to make them symmetric.

Signed-off-by: Bodong Wang <bodong@mellanox.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>