common/mlx5: check connection tracking offload capability

common/mlx5: check connection tracking offload capability

During startup, the ASO connection tracking offload capability could
be queried via HCA_CAP_QUERY command. If the HW doesn't support ASO
CT, the value would be 0 by default. The following initialization
should be skipped and the creation of the CT object should return
a failure directly.

The following CT creation should also check this capability. With
the old driver, the pre-processing macro should be used in order to
make the compiling pass.

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