hw/nubus: add nubus-virtio-mmio device

hw/nubus: add nubus-virtio-mmio device

The nubus-virtio-mmio device is a Nubus card that contains a set of 32 virtio-mmio
devices and a goldfish PIC similar to the m68k virt machine that can be plugged
into the m68k q800 machine.

There are currently a number of drivers under development that can be used in
conjunction with this device to provide accelerated and/or additional hypervisor
services to 68k Classic MacOS.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-ID: <20240111102954.449462-4-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>