RDMA/hns: Use new interface to set MPT related fields

mainline inclusion
from mainline-v5.12-rc1
commit dc504774
category: bugfix
bugzilla: 174002
CVE:NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dc504774408b8ee6ce4967fbacb8b0d56588dc71

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Achieve hr_reg_write() to simply the codes to fill fields.

Link: https://lore.kernel.org/r/1611395282-991-4-git-send-email-liweihang@huawei.com


Signed-off-by: Lang Cheng <chenglang@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: wangsirong <wangsirong@huawei.com>
Reviewed-by: ChunZhi Hu <huchunzhi@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>