net: write enetaddr down to hardware on env_callback

If mac-address is changed using "setenv ethaddr ...." command the new
mac-adress also must be written into the responsible ethernet driver.
This fixes the legacy ethernet handling.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Hannes Schmelzer <oe5hpm@oevsv.at>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Cc: Tom Rini <trini@konsulko.com>
Reviewed-by: Hannes Schmelzer <oe5hpm@oevsv.at>
diff --git a/net/eth_legacy.c b/net/eth_legacy.c
index d6d7cee..1354f49 100644
--- a/net/eth_legacy.c
+++ b/net/eth_legacy.c
@@ -118,6 +118,7 @@
 			case env_op_create:
 			case env_op_overwrite:
 				eth_parse_enetaddr(value, dev->enetaddr);
+				eth_write_hwaddr(dev, "eth", dev->index);
 				break;
 			case env_op_delete:
 				memset(dev->enetaddr, 0, 6);