liblights: updates & fixes

Fade lights based on ALS value
Add option to disable keyboard or button backlight
Fix some compiler warnings

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

Change-Id: Ifd6ace89210cab761b38f48225778822236d3f91
liblights: partial revert of changes

I need to learn to try my changes before submitting them...

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

Change-Id: Iceae7d40798d338c290ec446477253989faaaca1
overlay: initial als range for buttons/keyboard

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

Change-Id: I64c72b236b3a1db48133b0dbce419c021ffa7b96
liblights: revert all my changes for now

I have to do actual testing before pushing the code

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

Change-Id: Idd13b62331351b4cf7c4f0bd418b7819ce5f9871