board: sama5d3xek: Convert to CONFIG_DM_VIDEO

Convert the board to support the video driver model, add the device
tree node, and remove the unnecessary code.

Signed-off-by: Wenyou Yang <wenyou.yang@microchip.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/dts/sama5d36ek_cmp.dts b/arch/arm/dts/sama5d36ek_cmp.dts
index be41490..c17bc9f 100644
--- a/arch/arm/dts/sama5d36ek_cmp.dts
+++ b/arch/arm/dts/sama5d36ek_cmp.dts
@@ -8,6 +8,7 @@
 /dts-v1/;
 #include "sama5d36.dtsi"
 #include "sama5d3xmb_cmp.dtsi"
+#include "sama5d3xdm.dtsi"
 
 / {
 	model = "Atmel SAMA5D36-EK";