net: w5100: increase TX timeout period

This increases TX timeout period from one second to 5 seconds which is
the default value if the driver doesn't explicitly set
net_device->watchdog_timeo.

The one second timeout is too short for W5100 with SPI interface mode
which doesn't support burst READ/WRITE processing in the SPI transfer.
If the packet is transmitted while RX packets are being received at a
very high rate, the TX transmittion work in the workqueue is delayed
and the watchdog timer is expired.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Mike Sinkovsky <msink@permonline.ru>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/wiznet/w5100.c

@@ -1142,7 +1142,6 @@ int w5100_probe(struct device *dev, const struct w5100_ops *ops,
 
 	ndev->netdev_ops = &w5100_netdev_ops;
 	ndev->ethtool_ops = &w5100_ethtool_ops;
-	ndev->watchdog_timeo = HZ;
 	netif_napi_add(ndev, &priv->napi, w5100_napi_poll, 16);
 
 	/* This chip doesn't support VLAN packets with normal MTU,