net/mlx5: Expose IP-in-IP capability bit

Expose Fw indication that it supports Stateless Offloads for IP over IP
tunneled packets. The following offloads are supported for the inner
packets: RSS, RX & TX Checksum Offloads, LSO and Flow Steering.

Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>