watchdog: w83627hf: Added NCT6102D support.

As used in (and tested on) the ASRock IMB-150 board. Implementation is
identical to other NCT chips, just with different registers.

Signed-off-by: Rob Kramer <rob@solution-space.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>