RDMA/hns: Fix mis-modifying default congestion control algorithm

Commit 27c5fd27 ("RDMA/hns: The UD mode can only be configured
with DCQCN") adds a check of congest control alorithm for UD. But
that patch causes a problem: hr_dev->caps.congest_type is global,
used by all QPs, so modifying this field to DCQCN for UD QPs causes
other QPs unable to use any other algorithm except DCQCN.

Revert the modification in commit 27c5fd27 ("RDMA/hns: The UD
mode can only be configured with DCQCN"). Add a new field cong_type
to struct hns_roce_qp and configure DCQCN for UD QPs.

Fixes: 27c5fd27 ("RDMA/hns: The UD mode can only be configured with DCQCN")
Fixes: f91696f2

 ("RDMA/hns: Support congestion control type selection according to the FW")
Signed-off-by: Luoyouming <luoyouming@huawei.com>
Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>
Link: https://lore.kernel.org/r/20240219061805.668170-1-huangjunxian6@hisilicon.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>