amd-xgbe: Add support for the netdev Tx watchdog

Add support to be able to detect a hung Tx task by adding the netdev
ndo_tx_timeout function callback. Do not set the watchdog_timeo value
so as to use the system default time (currently 5 seconds).

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-main.c b/drivers/net/ethernet/amd/xgbe/xgbe-main.c
index 2e4c22d9..7149053 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-main.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-main.c
@@ -491,6 +491,9 @@
 
 	netdev->priv_flags |= IFF_UNICAST_FLT;
 
+	/* Use default watchdog timeout */
+	netdev->watchdog_timeo = 0;
+
 	xgbe_init_rx_coalesce(pdata);
 	xgbe_init_tx_coalesce(pdata);