kirkwood: do not expose status LED to user config by default
So far, the state of status LEDs is set up in 01_leds for many devices
in kirkwood target. As those LEDs are also controlled by diag.sh,
exposing them to the user via uci config by default seems not helpful
and might even have confusing results for the user.
Thus, remove the ucidef_set_led_default setup for power/status LED, but
do not touch the rest where user control is actually a feature.
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>