Do not require virtio-pci devices when using virtio-mmio

On arm, we probe for virtio-*-pci devices, but use their
virtio-*-device variants.

Set the capabilities based on the -device variants as well,
to make them work with qemus with the PCI devices compiled out.

src/qemu/qemu_capabilities.c

@@ -1499,6 +1499,7 @@ struct virQEMUCapsStringFlags virQEMUCapsObjectTypes[] = {
     { "virtio-scsi-pci", QEMU_CAPS_VIRTIO_SCSI },
     { "virtio-scsi-s390", QEMU_CAPS_VIRTIO_SCSI },
     { "virtio-scsi-ccw", QEMU_CAPS_VIRTIO_SCSI },
+    { "virtio-scsi-device", QEMU_CAPS_VIRTIO_SCSI },
     { "megasas", QEMU_CAPS_SCSI_MEGASAS },
     { "spicevmc", QEMU_CAPS_DEVICE_SPICEVMC },
     { "qxl-vga", QEMU_CAPS_DEVICE_QXL_VGA },
@@ -1515,6 +1516,7 @@ struct virQEMUCapsStringFlags virQEMUCapsObjectTypes[] = {
     { "virtio-rng-pci", QEMU_CAPS_DEVICE_VIRTIO_RNG },
     { "virtio-rng-s390", QEMU_CAPS_DEVICE_VIRTIO_RNG },
     { "virtio-rng-ccw", QEMU_CAPS_DEVICE_VIRTIO_RNG },
+    { "virtio-rng-device", QEMU_CAPS_DEVICE_VIRTIO_RNG },
     { "rng-random", QEMU_CAPS_OBJECT_RNG_RANDOM },
     { "rng-egd", QEMU_CAPS_OBJECT_RNG_EGD },
     { "spapr-nvram", QEMU_CAPS_DEVICE_NVRAM },