IB/hfi1: Allow for extra entries in QP's s_ack_queue

The TID RDMA WRITE protocol differs from normal IB RDMA WRITE
in that TID RDMA WRITE requests do require responses, not just
ACKs.

Therefore, TID RDMA WRITE requests need to be treated as RDMA
READ requests from the point of view of the QPs' s_ack_queue.
In other words, the QPs' need to allow for TID RDMA WRITE
requests to be stored in their s_ack_queue.

However, because the user does not know anything about the TID
RDMA capability and/or protocols, these extra entries in the
queue cannot be advertized to the user.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Mitko Haralanov <mitko.haralanov@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>