The later macbook models use a different packet payload for the light sensors:
- there's only one, done in the camera
- it's a 4 byte value, not a 2 byte value
- it's in a 10 byte payload
So, this adds support for that and flips it on for the MacbookAir 6,2.
It also adds support for MacBookAir 6,1 as that now works fine here.