lantiq: fix led setup after switch to uci-defaults-new.sh

lantiq: fix led setup after switch to uci-defaults-new.sh

The switch to uci-defaults-new.sh revealed a bug in the former used
uci-defaults.sh, which failed to add leds with colons in the led name.

This bug isn't any longer present in uci-defaults-new.sh and therefore
all via DT defined leds will be added to /etc/config/system with their initial
on/off state, regardless whether they are already added by the board specific
led mappings.

This results for a BTHOMEHUBV5A into the following led configuration:

- soc:blue:power is added as led_power with the initial state "switched on"
- soc:blue:power is added as led_soc_blue_power with the initial state "switched off"

With the final result of a switched off power led after boot.

The only led that needs to be added is the BTHOMEHUBV5A specific dimmed led.

Signed-off-by: Mathias Kresin <openwrt@kresin.me>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@47850 3c298f89-4303-0410-b956-a3cf2f4a3e73