IB/CM: Set appropriate slid and dlid when handling CM request

If extended LIDs are being used, a connection request contains
OPA GIDs in them. Extract the lids from the OPA gids and populate
slid/dlid fields in the path records that are created when handling
a connection request.

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