RDMA/hns: Remove unused declaration hns_roce_modify_srq()

Commit c7bcb134 ("RDMA/hns: Add SRQ support for hip08 kernel mode")
declared but never implemented this.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20230804130418.41728-1-yuehaibing@huawei.com


Reviewed-by: Junxian Huang <huangjunxian6@hisilicon.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>