net/mlx5: Set reformat action when needed for termination rules

For remote mirroring, after the tunnel packets are received, they are
decapsulated and sent to representor, then re-encapsulated and sent
out over another tunnel. So reformat action is set only when the
destination is required to do encapsulation.

Fixes: 249ccc3c ("net/mlx5e: Add support for offloading traffic from uplink to uplink")
Signed-off-by: Jianbo Liu <jianbol@nvidia.com>
Reviewed-by: Ariel Levkovich <lariel@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>