Add external graphics card on Jetson AGX Xavier Developer Kit

At the moment, no. The drivers for the integrated GPU work only when the GPU is integrated directly to the memory controller, whereas external GPUs are used over PCIe. The drivers are incompatible. There are some arm64 drivers at some download URLs, but those are intended for data warehouse arm64, and are unlikely to work with a Jetson. I’ve seen people ask about this, and I suspect NVIDIA is considering it, but I have not heard of such a thing being implemented (yet).