While we'd like to convert ar71xx to DT-based configuration
eventually, we aren't quite there yet, and shipping half-baked DT support
that is not used at all wastes precious space.
Saves ~120KB before LZMA, ~33KB after LZMA.
Run-tested on TP-Link CPE510 and TL-WR841 v7.
Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
