hw/virtio: Add VirtioPCIDeviceTypeInfo::instance_finalize field

hw/virtio: Add VirtioPCIDeviceTypeInfo::instance_finalize field

The VirtioPCIDeviceTypeInfo structure, added in commit a4ee4c8baa
("virtio: Helper for registering virtio device types") got extended
in commit 8ea90ee690 ("virtio: add class_size") with the @class_size
field. Do similarly with the @instance_finalize field.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20231121174051.63038-2-philmd@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>