net/mlx5: fix tunneling support query

net/mlx5: fix tunneling support query

Currently, the PMD decides if the tunneling offload
can enable VXLAN/GRE/GENEVE tunneled TSO support by checking
config->tunnel_en (single bit) and config->tso.

This is incorrect, the right way is to check the following
flags returned by the mlx5dv_query_device function:

MLX5DV_RAW_PACKET_CAP_TUNNELED_OFFLOAD_VXLAN - if supported the offload
DEV_TX_OFFLOAD_VXLAN_TNL_TSO can be enabled.
MLX5DV_RAW_PACKET_CAP_TUNNELED_OFFLOAD_GRE - if supported the offload
DEV_TX_OFFLOAD_GRE_TNL_TSO can be enabled.
MLX5DV_RAW_PACKET_CAP_TUNNELED_OFFLOAD_GENEVE - if supported the offload
DEV_TX_OFFLOAD_GENEVE_TNL_TSO can be enabled.

The fix enables the offloads according to the correct
flags returned by the kernel.

Fixes: dbccb4cddcd2 ("net/mlx5: convert to new Tx offloads API")
Cc: stable@dpdk.org
Signed-off-by: Tal Shnaiderman <talshn@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>
Tested-by: Idan Hackmon <idanhac@nvidia.com>