hwmon: (applesmc) Add generic support for MacBook Pro 6

This patch adds generic support for the MacBook Pro 6 family
based on the 6,2 model.

[rydberg@euromail.se: patch cleanup]
Signed-off-by: Bernhard Froemel <froemel@vmars.tuwien.ac.at>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Jean Delvare <khali@linux-fr.org>