RDMA/ocrdma: Prevent CQ-Doorbell floods

Changing CQ-Doorbell(DB) logic to prevent DB floods, it is supposed to be
pressed only if any hw CQE is polled. If cq-arm was requested
previously then don't bother about number of hw CQEs polled and
arm the CQ.

Signed-off-by: Devesh Sharma <devesh.sharma@avagotech.com>
Signed-off-by: Selvin Xavier <selvin.xavier@avagotech.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>