RDMA/hns: Optimize qp param setup flow

Encapsulate the qp param setup related code into set_qp_param().

Link: https://lore.kernel.org/r/1582526258-13825-6-git-send-email-liweihang@huawei.com


Signed-off-by: Xi Wang <wangxi11@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>