libvirtd: enable virtlockd/virtlogd socket activation on install
    
    When someone does 'systemctl enable libvirtd.service' we should
    also enable virtlockd.socket/virtlogd.socket, so that they can
    be auto-activated if libvirtd tries to access the sockets.
    
    Without this, people have to manually enable the units themselves
    via 'systemctl enable virtdlogd.socket'.
    
    This also ensures that if distros uses  'systemctl preset' for
    enabling 'libvirtd.service', then the virtdlogd.socket gets
    enabled without having to wait for the distro to update their
    presets file.
    
    Signed-off-by: Daniel P. Berrange <berrange@redhat.com>