Author: Sean.Hung <https://github.com/seanhungtw/belkin_rt1800_openwrt>
porting from https://github.com/padavanonly (immortalwrt mirror)
limitation: 1. Can't use DSA switch, rollback to swconfig
2. wifi interface name is hardcoded in the dts,
currently only support "phy0-ap0", "phy1-ap0", "phy0-ap1", "phy1-ap1",
"phy0-sta0", "phy1-sta0"