net: ethernet: ti: cpsw: wake tx queues on ndo_tx_timeout

In case, if TX watchdog is fired some or all netdev TX queues will be
stopped and as part of recovery it is required not only to drain and
reinitailize CPSW TX channeles, but also wake up stoppted TX queues what
doesn't happen now and netdevice will stop transmiting data until
reopenned.

Hence, add netif_tx_wake_all_queues() call in .ndo_tx_timeout() to complete
recovery and restore TX path.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>