configs: clearfog: enable random random MAC address
This makes the network devices usable when booting a blank board over
UART, with no pre-configured MAC address stored in the environment area.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Stefan Roese <sr@denx.de>