net: hns3: reset tqp while doing DOWN operation

While doing DOWN operation, the driver will reclaim the memory which has
already used for TX. If the hardware is processing this memory, it will
cause a RCB error to the hardware. According the hardware's description,
the driver should reset the tqp before reclaim the memory during DOWN.

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>