IB/rdmavt: Add pkey query stub

The pkey table will reside in the rvt structure but it will be modified
only when the driver requests then rvt will simply read the value to return
in the query.

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>

include/rdma/rdma_vt.h

@@ -114,12 +114,13 @@ struct rvt_dev_info {
 	 * The driver will also be responsible for filling in certain members of
 	 * dparms.props
 	 */
-
 	struct ib_device ibdev;
 
 	/* Driver specific properties */
 	struct rvt_driver_params dparms;
 
+	/* PKey Table goes here */
+
 	/*
 	 * The work to create port files in /sys/class Infiniband is different
 	 * depending on the driver. This should not be extracted away and