bcm53xx: fix LAN MAC address for devices that use eth2 originally

We override default Ethernet interface with eth0 which often uses random
MAC due to missing proper NVRAM entry. Fix this by manually assigning
MAC in the config.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

target/linux/bcm53xx/base-files/etc/board.d/02_network

@@ -50,6 +50,12 @@ netgear,r8500)
 	ifname=eth0
 	ucidef_add_switch "switch0" \
 		"0:lan" "1:lan" "2:lan" "3:lan" "4:wan" "5t@$ifname"
+
+	# These devices should use eth2 so their eth0 interface often has no MAC
+	# assigned. Manually assign eth2's MAC to the LAN.
+	et2macaddr="$(nvram get et2macaddr)"
+	[ -n "$et2macaddr" ] && ucidef_set_interface_macaddr "lan" "$et2macaddr"
+
 	board_config_flush
 	exit 0
 	;;