common/mlx5: add connection tracking object

common/mlx5: add connection tracking object

The structures of ASO connection tracking offload object are added
based on the definitions in the PRM. One CT object context will be
loaded into the cache completely in a reversed order of dwords. The
valid bit should be the MSB of the last dword. This is used for the
conntrack context creation and update, as well as for the query.

The capabilities 2 (HCA_CAP_2) layout is also added. The connection
tracking related capabilities could be queried via the HCA_CAP_2.

Signed-off-by: Bing Zhao <bingz@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>