verbs: cq_data_size

Include cq_data_size in fi_domain_attr when fi_getinfo returns in verbs provider.

Signed-off-by: Arun C Ilango <arun.ilango@intel.com>
This approach doesn't quite work.  Immediate data is only supported over IB devices.  iWarp devices need to report 0 here (at least for now -- the iWarp spec is being extended to add this capability, but no current devices provide this).