IB/rdmavt: Add ib core device attributes to rvt driver params list

IB/rdmavt: Add ib core device attributes to rvt driver params list

Instead of trying to handle each parameter separately, add ib_device_attr
to rvt_driver_params. This means drivers will fill this in and pass to the
rvt registration function.

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>