stubs: add isa_create_simple
Needed for -soundhw cleanup.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200702132525.6849-2-kraxel@redhat.com