Add a single QEMU_CAPS_VIRTIO_PCI_TRANSITIONAL that
will be set if any of the following qemu devices are found:

    virtio-blk-pci-transitional
    virtio-blk-pci-non-transitional
    virtio-net-pci-transitional
    virtio-net-pci-non-transitional
    vhost-scsi-pci-transitional
    vhost-scsi-pci-non-transitional
    virtio-rng-pci-transitional
    virtio-rng-pci-non-transitional
    virtio-9p-pci-transitional
    virtio-9p-pci-non-transitional
    virtio-balloon-pci-transitional
    virtio-balloon-pci-non-transitional
    vhost-vsock-pci-transitional
    vhost-vsock-pci-non-transitional
    virtio-input-host-pci-transitional
    virtio-input-host-pci-non-transitional
    virtio-scsi-pci-transitional
    virtio-scsi-pci-non-transitional
    virtio-serial-pci-transitional
    virtio-serial-pci-non-transitional
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>
Signed-off-by: NCole Robinson <crobinso@redhat.com>