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. I'll add a separate commit for MacBookAir 6,1 to introduce asmc support.