U-Boot only supports a subset of the devices supported by QEMU. For
example, U-Boot does not currently support the vsock device.
It is helpful to see what devices are provided by QEMU and whether there
is a driver for it in U-Boot.
Add a new 'virtio list' command to provide this.
Signed-off-by: Simon Glass <sjg@chromium.org>
bbd1cc14c1