net/mlx5e: kTLS, Enforce HW TX csum offload with kTLS

Checksum calculation cannot be done in SW for TX kTLS HW offloaded
packets.
Offload it to the device, disregard the declared state of the TX
csum offload feature.

Fixes: d2ead1f3 ("net/mlx5e: Add kTLS TX HW offload support")
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Boris Pismenny <borisp@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>