net: hns: Bugfix for Tx timeout handling in hns driver

When hns port type is not debug mode, netif_tx_disable is called
when there is a tx timeout, which requires system reboot to return
to normal state. This patch fix this problem by resetting the net
dev.

Fixes: b5996f11 ("net: add Hisilicon Network Subsystem basic ethernet support")
Signed-off-by: Lin Yun Sheng <linyunsheng@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>