ipq40xx: fix Netgear RBR40 wan mac

The WAN port currently has the same MAC set as all the other LAN ports.
Fix this by adding the missing case in ipq40xx_setup_macs().

Signed-off-by: Christoph Krapp <achterin@gmail.com>
Link: openwrt/openwrt#20877
Signed-off-by: Robert Marko <robimarko@gmail.com>

Author: achterin

target/linux/ipq40xx/base-files/etc/board.d/02_network

@@ -244,6 +244,7 @@ ipq40xx_setup_macs()
 		lan_mac=$(cat /sys/firmware/mikrotik/hard_config/mac_base)
 		label_mac="$lan_mac"
 		;;
+	netgear,rbr40|\
 	netgear,rbr50|\
 	netgear,srr60|\
 	pakedge,wr-1)