* Add support to HAL for APB frequencies different than 80MHz
* Add support for CPU frequencies in the IDE board menu
* Switch to fast set_config
* Add method to uart so debug can be reassigned after apb frequency switch
* Return real APB frequency
The esp-idf expects duty values for the the sigma delta modulator in the range of -128 to 127
The arduino framework is supposed to use the range 0-255 thus the offset caclulation was wrong.