IB/cm: Use the source GID index type

Previosuly, cm and cma modules supported only IB and RoCE v1 GID type.
In order to support multiple GID types, the gid_type is passed to
cm_init_av_by_path and stored in the path record.

The rdma cm client would use a default GID type that will be saved in
rdma_id_private.

Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>