RDMA/ocrdma: remove reference of ocrdma_dev out of ocrdma_qp structure

Use get_ocrdma_dev(ocrdma_qp->ibqp.device) function to access ocrdma
device pointer.

Signed-off-by: Mitesh Ahuja <mitesh.ahuja@emulex.com>
Signed-off-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Selvin Xavier <selvin.xavier@emulex.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>