drm: introduce bus_flags in drm_display_info

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: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Manfred Schlaegl <manfred.schlaegl@gmx.at>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Stefan Agner <stefan@agner.ch>
diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index ceb2048..77ae07f 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -72,6 +72,7 @@
 	} delay;
 
 	u32 bus_format;
+	u32 bus_flags;
 };
 
 struct panel_simple {
@@ -144,6 +145,7 @@
 	if (panel->desc->bus_format)
 		drm_display_info_set_bus_formats(&connector->display_info,
 						 &panel->desc->bus_format, 1);
+	connector->display_info.bus_flags = panel->desc->bus_flags;
 
 	return num;
 }