IB/qib: Remove qpn, qp tables and related variables from qib

This patch removes the private queue pair structure and the table which
holds the queue pair numbers in favor of using what is provided by rdmavt.

Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Harish Chegondi <harish.chegondi@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>