The 'vexpress-a9' ARM board supports the native 'sd' bus as well as
virtio. Add a test case for proving that upcoming changes to handling of
'sd' work. This config was also tested with real qemu and the qemu
process starts correctly.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>