rockchip: configs: Enable CONFIG_NET_RANDOM_ETHADDR for rk3288-evb

If the Ethernet address is not set, the network can't work,
enable the random address config for default use.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
diff --git a/configs/evb-rk3288_defconfig b/configs/evb-rk3288_defconfig
index c10bec2..09a8844 100644
--- a/configs/evb-rk3288_defconfig
+++ b/configs/evb-rk3288_defconfig
@@ -33,6 +33,7 @@
 CONFIG_SPL_OF_CONTROL=y
 CONFIG_OF_SPL_REMOVE_PROPS="pinctrl-0 pinctrl-names clock-names interrupt-parent assigned-clocks assigned-clock-rates assigned-clock-parents"
 CONFIG_ENV_IS_IN_MMC=y
+CONFIG_NET_RANDOM_ETHADDR=y
 CONFIG_REGMAP=y
 CONFIG_SPL_REGMAP=y
 CONFIG_SYSCON=y