mango: Remove obsolete ALS configuration

Also set button_backlight current on pre_hw_config.sh to avoid too bright recovery indication.

Signed-off-by: Michael Bestas <mikeioannina@gmail.com>

Change-Id: I948e9495917b94e4995c5cdffff933004d802a5c
mango: Fix leds & backlight configuration on boot

Signed-off-by: Michael Bestas <mikeioannina@gmail.com>

Change-Id: I686ace45cee09a32a73b21be268b209ce08121d4