Add USB-C support for Rock 5B
Radxa Rock 5B has a FUSB302 USB-C controller, which takes care of PD negotiation, cable orientation and informing about available Alt modes. The chip already has an upstream driver and is enabled in the arm64 defconfig, since it is quite common. Enabling support in Rock 5B is a bit tricky, since the board is usually powered from the USB-C port. If negotiation is not done correctly the board will reset because of a power-loss shortly after the driver is probed. On the EVB1 this is not an issue, since the board is not powered through USB-C.
Note, that properly handling FUSB302 is not just required for USB-PD, but also to get functional USB2/USB3/DP Altmode for the USB-C port on the Rock 5B.