hwmon: applesmc: add support for Macbook 5

Add accelerometer, backlight and temperature sensor support for the new
unibody Macbook 5.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Tested-by: David M. Lary <dmlary@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>