IB/hfi1: Return invalid field for non-QSFP CableInfo queries

The driver does not check if the CableInfo query is supported for the
port type. Return early if CableInfo is not supported for the port type,
making compliance with the specification explicit and preventing lower
level code from potentially doing the wrong thing if the query is not
supported for the hardware implementation.

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Easwar Hariharan <easwar.hariharan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>