hwmon: (applesmc) Add MacBookAir3,1(3,2) support

This patch add support for the MacBookAir3,1 and MacBookAir3,2 to the
applesmc driver.

[rydberg@euromail.se: minor cleanup]
Cc: stable@kernel.org
Signed-off-by: Edgar Hucek <gimli@dark-green.com>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>