RDMA/hns: Remove support for HIP08_A

HIP08_A is an temporary version and all features of it are supported by
HIP08_B. So remove the relevant code.

Link: https://lore.kernel.org/r/1595932941-40613-4-git-send-email-liweihang@huawei.com


Signed-off-by: Lang Cheng <chenglang@huawei.com>
Signed-off-by: Yangyang Li <liyangyang20@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>