hwmon: Add support for the Winbond W83687THF

Add support for the Winbond W83687THF chip to the w83627hf hardware
monitoring driver. This new chip is almost similar to the already
supported W83627THF chip, except for VID and a few other minor
changes.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>