hwmon: (adt7475) Fix default duty on fan is disabled

According to the comments on fan is disabled, we change to manual mode
and set the duty cycle to 0.
For setting the duty cycle part, the register is wrong. Fix it.

Fixes: 1c301fc5 ("hwmon: Add a driver for the ADT7475 hardware monitoring chip")
Signed-off-by: Wayne Tung <chineweff@gmail.com>
Link: https://lore.kernel.org/r/20240701073252.317397-1-chineweff@gmail.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>