Add USB-PD negotiation support via CCx pins

[ryan-summers]

Add support for USB-PD negotiation to negotiate a higher VBUS input voltage. This will eliminate the need for the external barrel-jack connector.

[ryan-summers]

Additional note - the intended use case of this board uses the USB port for communications. It is unlikely that the USB host will be capable of supplying higher VBUS voltages unless an external, powered USB-PD compatible USB hub is used.