RDMA/hns: Support get XRCD number from firmware

Support driver get the num of XRCD from firmware.

Signed-off-by: Luoyouming <luoyouming@huawei.com>
Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>
Link: https://lore.kernel.org/r/20230721025146.450831-2-huangjunxian6@hisilicon.com


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