Some of the boards supported by this driver only have differential analog inputs. Add a new boardinfo, 'ai_subdev_flags', to allow properly setting the subdev_flags for the analog input subdevice. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Reviewed-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>