imx: make ipu's di configurable

The ipu has two display interfaces. Make the used one a parameter
in struct display_info_t instead of using unconditionally DI0.
DI0 is the default setting.

Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Reviewed-by: Eric Nelson <eric@nelint.com>

arch/arm/imx-common/video.c

@@ -34,7 +34,7 @@ int board_video_skip(void)
 	}
 
 	if (i < display_count) {
-		ret = ipuv3_fb_init(&displays[i].mode, 0,
+		ret = ipuv3_fb_init(&displays[i].mode, displays[i].di ? 1 : 0,
 				    displays[i].pixfmt);
 		if (!ret) {
 			if (displays[i].enable)

arch/arm/include/asm/imx-common/video.h

@@ -12,6 +12,7 @@ struct display_info_t {
 	int	bus;
 	int	addr;
 	int	pixfmt;
+	int	di;
 	int	(*detect)(struct display_info_t const *dev);
 	void	(*enable)(struct display_info_t const *dev);
 	struct	fb_videomode mode;