Brake out USB lines from PD port

A load of boards, raspberry pi 0/4/5/CM4/CM5, rock5b, Nvidia use the power USB A/C port for flashing/recovery.

We should be able to use the usb lines from the usb-C port we use for PD.

We should be able to flash a pi/rock5 from the PD port eg https://github.com/raspberrypi/usbboot

I can think of a lot of ways to support this but just braking them out to a usb port next to the usb pd port is probably the simplest solution. having a option to connect it to the internal hub might be nice but that sounds quite complex.