pci: Make host bridge TypeInfos const During the QOM migration they were amended with further info but this is no longer the case. All static TypeInfos can be const these days. Signed-off-by: Andreas Färber <afaerber@suse.de> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>