main: Add IIO buffering Light Sensor driver
Created by: elad661
Such as the one on the Thinkpad Twist.
I tested this on my device and it seems to work sporadically due to driver bugs (and probably shitty hardware).
It's based on the buffer accelerometer code, with few minor changes to make it read from the light sensor.
The values I'm getting from my sensor are too high to be in Lux (about 10 time bigger than the readings from the colorHug ALS), but I didn't want to apply a quirk to them because I assume other types of sensors would not have the same issue.