board: sama5d4ek: 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/configs/sama5d4ek_nandflash_defconfig b/configs/sama5d4ek_nandflash_defconfig
index 901d17b..94970c6 100644
--- a/configs/sama5d4ek_nandflash_defconfig
+++ b/configs/sama5d4ek_nandflash_defconfig
@@ -75,4 +75,5 @@
 CONFIG_USB_STORAGE=y
 CONFIG_USB_GADGET=y
 CONFIG_USB_GADGET_ATMEL_USBA=y
-CONFIG_LCD=y
+CONFIG_DM_VIDEO=y
+CONFIG_ATMEL_HLCD=y