RDMA/hns: Add window selection field of congestion control

The window selection field is necessary for congestion control of HIP09,
it is got from firmware and then filled into QPC. Some algorithms need it
to decide whether to limit the number of windows.

Fixes: f91696f2

 ("RDMA/hns: Support congestion control type selection according to the FW")
Link: https://lore.kernel.org/r/1624364163-44185-1-git-send-email-liweihang@huawei.com
Signed-off-by: Yixing Liu <liuyixing1@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>