hwmon: (npcm750-pwm-fan) Use devm_thermal_of_cooling_device_register

Use devm_thermal_of_cooling_device_register() to register the cooling
device. As a side effect, this fixes a driver bug:
thermal_cooling_device_unregister() was not called on device removal.

Fixes: f1fd4a4db777 ("hwmon: Add NPCM7xx PWM and Fan driver")
Cc: Tomer Maimon <[e-mail]>
Signed-off-by: Guenter Roeck <[e-mail]>
Signed-off-by: Eduardo Valentin <[e-mail]>

drivers/hwmon/npcm750-pwm-fan.c

···
 	snprintf(cdev->name, THERMAL_NAME_LENGTH, "%pOFn%d", child,
 		 pwm_port);
 
-	cdev->tcdev = thermal_of_cooling_device_register(child,
-							 cdev->name,
-							 cdev,
-							 &npcm7xx_pwm_cool_ops);
+	cdev->tcdev = devm_thermal_of_cooling_device_register(dev, child,
+				cdev->name, cdev, &npcm7xx_pwm_cool_ops);
 	if (IS_ERR(cdev->tcdev))
 		return PTR_ERR(cdev->tcdev);