net: hns: Add reset function support for RoCE driver

It added reset function for RoCE driver. RoCE is a feature of hns.
In hip06 SoC, in RoCE reset process, it's needed to configure dsaf
channel reset, port and sl map info. Reset function of RoCE is
located in dsaf module, we only call it in RoCE driver when needed.

This patch is used to fix the conflict, please refer to this link:
  https://www.spinics.net/lists/linux-rdma/msg39114.html

Signed-off-by: Wei Hu <xavier.huwei@huawei.com>
Signed-off-by: Nenglong Zhao <zhaonenglong@hisilicon.com>
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Sheng Li <lisheng011@huawei.com>
Reviewed-by: Yisen Zhuang <yisen.zhuang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>