board: sama5d4_xplained: 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/sama5d4_xplained_spiflash_defconfig b/configs/sama5d4_xplained_spiflash_defconfig
index 4061720..d37be67 100644
--- a/configs/sama5d4_xplained_spiflash_defconfig
+++ b/configs/sama5d4_xplained_spiflash_defconfig
@@ -77,3 +77,5 @@
 CONFIG_USB_STORAGE=y
 CONFIG_USB_GADGET=y
 CONFIG_USB_GADGET_ATMEL_USBA=y
+CONFIG_DM_VIDEO=y
+CONFIG_ATMEL_HLCD=y