1. Fix the duty fade check issue reported from https://github.com/espressif/esp-idf/issues/1914
2. Fix the duty overflow issue when duty_scale is set to 1.
3. Fix the duty fade error when a fade operation is under way. We must configure a new duty setting after the previous fade operation has finished due to hardware limit.
4. Add thread-safe version APIs to set duty and fade.
5. Correct the duty range in driver.