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_mmc_defconfig b/configs/sama5d4ek_mmc_defconfig
index aaa5855..7367b6c 100644
--- a/configs/sama5d4ek_mmc_defconfig
+++ b/configs/sama5d4ek_mmc_defconfig
@@ -78,4 +78,5 @@
 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