ramips: extract default lan_mac from eth0

The default case of ramips_setup_macs() is useful when mtd-mac-address is defined in dts.
But lan_mac is not set by default, this results in lan and wan having the same mac.

Signed-off-by: Roman Yeryomin <roman@advem.lv>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@41632 3c298f89-4303-0410-b956-a3cf2f4a3e73

target/linux/ramips/base-files/etc/uci-defaults/02_network

@@ -258,6 +258,7 @@ ramips_setup_macs()
 		;;
 
 	*)
+		lan_mac=$(cat /sys/class/net/eth0/address)
 		wan_mac=$(macaddr_add "$lan_mac" 1)
 		;;