hwmon: (it87) Fix manual fan speed control on IT8721F

The manual fan speed control logic of the IT8721F is much different
from what older devices had. Update the code to properly support that.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
1 file changed