Introduce bus_flags to specify display bus properties like signal
polarities. This is useful for parallel display buses, e.g. to
specify the pixel clock or data enable polarity.
Suggested-by: NThierry Reding <thierry.reding@gmail.com>
Acked-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Acked-by: NManfred Schlaegl <manfred.schlaegl@gmx.at>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NStefan Agner <stefan@agner.ch>