IB/rdmavt: Add query and modify device stubs

Adds the stubs which will handle the query and modify device functions. At
this time the only intention is to support changing the node desc and the
guid via these calls.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>