ramips: initialize youhua, wr1200js WAN MAC addresses from flash

This patch changes wan MAC address setup for youhua,wr1200js
from retrieving it by calculation to reading it from flash.

This has been checked on-device.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

target/linux/ramips/base-files/etc/board.d/02_network

@@ -563,6 +563,7 @@ ramips_setup_macs()
 	phicomm,k2p|\
 	planex,vr500|\
 	samknows,whitebox-v8|\
+	youhua,wr1200js|\
 	youku,yk-l2|\
 	zbtlink,zbt-we3526)
 		wan_mac=$(mtd_get_mac_binary factory 0xe006)