RDMA/hns: Modify hns_roce_hw_v2_get_cfg to simplify the code

Merge base configuration of hr_dev into hns_roce_hw_v2_get_cfg(). In
addition, there is no need to return 0 at last, so we change return type
of it to void.

Link: https://lore.kernel.org/r/1572952082-6681-8-git-send-email-liweihang@hisilicon.com


Signed-off-by: Lang Cheng <chenglang@huawei.com>
Signed-off-by: Weihang Li <liweihang@hisilicon.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>