ar71xx: fix ath9k default LED changes fallout

Since 192f0a3d ("ath9k: unset the default LED pin if used by
platform leds") the default ath9k wireless LED is not set as soon as
any pin of the ath ath9k gpio controller is used.

All touched boards have leds defined which are using the gpio pins
exposed by the ath9k driver but rely on a default set wireless led
trigger.

Add the wireless leds were missing and setup the wireless phy trigger
in userspace.

Signed-off-by: Russell Senior <russell@personaltelco.net>
Signed-off-by: Mathias Kresin <dev@kresin.me>