asmc: add support for 10 byte light sensor payloads

[adrian]

Summary

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.

Test Plan

Tested on MacbookAir 6,1 and MacbookAir 6,2

[adrian]

sys/dev/asmc/asmcvar.h

73

hm, don't need these in this commit, i'll delete em before landing

[markj]

sys/dev/asmc/asmc.c

160

Extra newline.

1559

10 byte?

1564

v should probably be unsigned?

1576

This can just be v = be32dec(&buf[6]);.

[adrian]

corrections!

[adrian]

oops

[adrian]

ok, try this one!

[markj]

Seems ok to me.