RDMA/hns: Support hns HW stats

Support query hns HW stats for rdma-tool to help debugging.

Signed-off-by: Chengchang Tang <tangchengchang@huawei.com>
Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>
Link: https://lore.kernel.org/r/20230816091812.2899366-3-huangjunxian6@hisilicon.com


Signed-off-by: Leon Romanovsky <leon@kernel.org>