net: hns3: fix a deadlock problem when config TC during resetting

When config TC during the reset process, may cause a deadlock, the flow is
as below:
                             pf reset start
                                 │
                                 ▼
                              ......
setup tc                         │
    │                            ▼
    ▼                      DOWN: napi_disable()
napi_disable()(skip)             │
    │                            │
    ▼                            ▼
  ......                      ......
    │                            │
    ▼                            │
napi_enable()                    │
                                 ▼
                           UINIT: netif_napi_del()
                                 │
                                 ▼
                              ......
                                 │
                                 ▼
                           INIT: netif_napi_add()
                                 │
                                 ▼
                              ......                 global reset start
                                 │                      │
                                 ▼                      ▼
                           UP: napi_enable()(skip)    ......
                                 │                      │
                                 ▼                      ▼
                              ......                 napi_disable()

In reset process, the driver will DOWN the port and then UINIT, in this
case, the setup tc process will UP the port before UINIT, so cause the
problem. Adds a DOWN process in UINIT to fix it.

Fixes: bb6b94a8

 ("net: hns3: Add reset interface implementation in client")
Signed-off-by: Jie Wang <wangjie125@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>