IB/hfi1: Acquire QSFP cable information on loopback

Currently, QSFP information is not queried
in cases where loopback was set up and QSFP module is
present.

Acquire QSFP information in case of loopback.

Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jan Sokolowski <jan.sokolowski@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>