librdmacm: use sockaddr_ib addressing if IB ACM is in use

librdmacm: use sockaddr_ib addressing if IB ACM is in use

If IB ACM route resolution succeeds, provide the user with
AF_IB addresses, rather than AF_INET or AF_INET6 addressing.
AF_IB identifies the local and remote devices directly,
eliminating the need to perform address resolution a second
time via rdma_resolve_addr.

AF_IB addresses are returned using sockaddr_ib as part of
rdma_getaddrinfo.

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