net/mlx5: DR, Avoid unnecessary csum recalculation on supporting devices

If as part of the actions the TTL of the packet is modified, the packet's
checksum needs to be recalculated. Connect-X6DX can handle this csum
recalculation natively. Older devices require this additional recalculation.

Signed-off-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Reviewed-by: Alex Vesker <valex@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>