ar71xx: Correct MAC address for WAN interface of Archer C7 v5

This device shares the network config with v4, thus the WAN MAC
also needs to be fixed the same way. However, the partition
where the MAC address resides has been changed.

Based on: openwrt#1726

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

target/linux/ar71xx/base-files/etc/board.d/02_network

@@ -604,6 +604,10 @@ ar71xx_setup_macs()
 		base_mac=$(mtd_get_mac_binary config 8)
 		wan_mac=$(macaddr_add "$base_mac" 1)
 		;;
+	archer-c7-v5)
+		base_mac=$(mtd_get_mac_binary info 8)
+		wan_mac=$(macaddr_add "$base_mac" 1)
+		;;
 	dgl-5500-a1|\
 	dir-825-c1)
 		wan_mac=$(mtd_get_mac_ascii nvram "wan_mac")