IB/hns: Modify the condition of notifying hardware loopback

This patch modified the condition of notifying hardware loopback.

In hip06, RoCE Engine has several ports, one QP is related
to one port. hardware only support loopback in the same port,
not in the different ports.

So, If QP related to port N, the dmac in the QP context equals
the smac of the local port N or the loop_idc is 1, we should
set loopback bit in QP context to notify hardware.

Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>