hwmon: (gpio-fan) Use devm_thermal_of_cooling_device_register

Call devm_thermal_of_cooling_device_register() to register the cooling
device. Also use devm_add_action_or_reset() to stop the fan on device
removal. This fixes a race condition since the fan was stopped before
the hwmon device was removed.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>