openwrt_core: use OpenWrt way to define LAN/WAN ports

package/base-files/files/etc/board.d/45-iopsys-network

-#!/bin/sh
-
-# Set default LAN, WAN and possibly switch interfaces for Iopsys
-
-
-source /lib/functions/uci-defaults.sh
-
-board_config_update
-
-# Have we been here done before?
-json_is_a network object && exit 0
-
-
-ethernetLanPorts="$(db -q get hw.board.ethernetLanPorts)"
-wanEthernetPort="$(db -q get hw.board.ethernetWanPort)"
-
-[ -n "$ethernetLanPorts" ] && ucidef_set_interface_lan "$ethernetLanPorts"
-
-if [ -n "$wanEthernetPort" ]; then # Ethernet WAN Port
-	ucidef_set_interface_wan "$wanEthernetPort"
-else # No Ethernet WAN Port found, check for PON
-	if [ -d /sys/module/bcmgpon ]; then # Broadcom PON
-		ucidef_set_interface_wan "veip0"
-	elif [ -d /sys/module/xpon ]; then # Airoha PON
-		ucidef_set_interface_wan "pon"
-	fi
-fi
-board_config_flush
-
-
-exit 0