net: Add CONFIG_NET_DO_NOT_TRY_ANOTHER option

When CONFIG_NET_DO_NOT_TRY_ANOTHER is defined U-Boot's
networking stack does not automatically switch to
another interface. This patch does not touch the default
behavior.

Signed-off-by: Matthias Fuchs <matthias.fuchs@esd-electronics.com>
Signed-off-by: Ben Warren <biggerbadderben@gmail.com>

net/net.c

@@ -596,7 +596,9 @@ void NetStartAgain (void)
 	NetSetHandler (startAgainHandler);
 #else	/* !CONFIG_NET_MULTI*/
 	eth_halt ();
+#if !defined(CONFIG_NET_DO_NOT_TRY_ANOTHER)
 	eth_try_another (!NetRestarted);
+#endif
 	eth_init (gd->bd);
 	if (NetRestartWrap) {
 		NetRestartWrap = 0;