RDMA/hns: Support 0 hop addressing for CQE buffer

Add the zero hop addressing support by using mtr interface for CQE buffer,
so the hns driver can support addressing hopnum between 0 to 3 for CQE.

Link: https://lore.kernel.org/r/1586779091-51410-7-git-send-email-liweihang@huawei.com


Signed-off-by: Xi Wang <wangxi11@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>