vfio/ap: Don't initialize HOST_IOMMU_DEVICE with mdev

mdevs aren't "physical" devices and when asking for backing IOMMU info,
it fails the entire provisioning of the guest. Fix that by setting
vbasedev->mdev true so skipping HostIOMMUDevice initialization in the
presence of mdevs.

Fixes: 930589520128 ("vfio/iommufd: Implement HostIOMMUDeviceClass::realize() handler")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

hw/vfio/ap.c

@@ -230,6 +230,9 @@ static void vfio_ap_instance_init(Object *obj)
      */
     vfio_device_init(vbasedev, VFIO_DEVICE_TYPE_AP, &vfio_ap_ops,
                      DEVICE(vapdev), true);
+
+    /* AP device is mdev type device */
+    vbasedev->mdev = true;
 }
 
 #ifdef CONFIG_IOMMUFD