imx: mx6ul_14x14_evk: configure for 24bpp display

Before DM_VIDEO conversion this board used 24bpp
display configuration, so use it again.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
diff --git a/arch/arm/dts/imx6ul-14x14-evk-u-boot.dtsi b/arch/arm/dts/imx6ul-14x14-evk-u-boot.dtsi
index e9efdb9..d0cbf79 100644
--- a/arch/arm/dts/imx6ul-14x14-evk-u-boot.dtsi
+++ b/arch/arm/dts/imx6ul-14x14-evk-u-boot.dtsi
@@ -31,7 +31,7 @@
 	u-boot,dm-pre-reloc;
 
 	display0: display@0 {
-		bits-per-pixel = <16>;
+		bits-per-pixel = <24>;
 		bus-width = <24>;
 
 		display-timings {