Enable support for the Ubiquiti UniFi Outdoor+ RF filter via
device-tree. The old way of using platform data is not required anymore,
as it was only used on the now removed ar71xx target.
Signed-off-by: David Bauer <mail@david-bauer.net>
Signed-off-by: CN_SZTL <cnsztl@project-openwrt.eu.org>