drm/sun4i: Add compatible for the A10s pipeline

The A10s has a slightly different display pipeline than the A13, with an
HDMI controller.

Add a compatible for it.
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt

@@ -210,6 +210,7 @@ extra node.
 
 Required properties:
   - compatible: value must be one of:
+    * allwinner,sun5i-a10s-display-engine
     * allwinner,sun5i-a13-display-engine
     * allwinner,sun6i-a31-display-engine
     * allwinner,sun6i-a31s-display-engine

drivers/gpu/drm/sun4i/sun4i_drv.c

@@ -305,6 +305,7 @@ static int sun4i_drv_remove(struct platform_device *pdev)
 }
 
 static const struct of_device_id sun4i_drv_of_table[] = {
+	{ .compatible = "allwinner,sun5i-a10s-display-engine" },
 	{ .compatible = "allwinner,sun5i-a13-display-engine" },
 	{ .compatible = "allwinner,sun6i-a31-display-engine" },
 	{ .compatible = "allwinner,sun6i-a31s-display-engine" },