ramips: replace MAC address configuration for I-O DATA WN-AC-GR devices

following I-O DATA devices have a MAC address as "wanaddr" for WAN
interface in u-boot-env:

- WN-AC1167GR
- WN-AC733GR3

I replaced MAC address configuration in these devices to omit
address calculation in 02_network.

Signed-off-by: INAGAKI Hiroshi <[email protected]>

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

@@ -663,7 +663,7 @@ ramips_setup_macs()
 		;;
 	iodata,wn-ac1167gr|\
 	iodata,wn-ac733gr3)
-		wan_mac=$(macaddr_add "$(mtd_get_mac_binary factory 0x4)" -1)
+		wan_mac=$(mtd_get_mac_ascii u-boot-env wanaddr)
 		;;
 	iodata,wn-ax1167gr|\
 	iodata,wn-gx300gr|\