USB-C device support

Samples that demonstrate the USB-C device stack.

• Basic USB-C DRPImplement a USB-C Power Delivery application in the form of a USB-C DRP (Dual Role Power).
• Basic USB-C SinkImplement a USB-C Power Delivery application in the form of a USB-C Sink.
• Basic USB-C SourceImplement a USB-C Power Delivery application in the form of a USB-C Source.