IB/SA: Add OPA path record type

Add opa_sa_path_rec to sa_path_rec data structure.
The 'type' field in sa_path_rec identifies the
type of the path record.

Reviewed-by: Don Hiatt <don.hiatt@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>