rdma/ucm: support querying for AF_IB addresses

rdma/ucm: support querying for AF_IB addresses

The sockaddr structure for AF_IB is larger than sockaddr_in6.
The rdma cm user space ABI uses the latter to exchange address
information between user space and the kernel.

To support querying for larger addresses, define a new query
command that exchanges data using sockaddr_storage, rather
than sockaddr_in6.  Unlike the existing query_route command,
the new command only returns address information.  Route
(i.e. path record) data is separated.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>