drm/sun4i: Add compatible strings for the A80 display pipeline

This patch adds compatible strings for the remaining documented
components of the Allwinner A80 display pipeline.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180315114136.24747-5-wens@csie.org

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

@@ -191,7 +191,7 @@ DRC
 ---
 
 The DRC (Dynamic Range Controller), found in the latest Allwinner SoCs
-(A31, A23, A33), allows to dynamically adjust pixel
+(A31, A23, A33, A80), allows to dynamically adjust pixel
 brightness/contrast based on histogram measurements for LCD content
 adaptive backlight control.
 
@@ -201,6 +201,7 @@ Required properties:
     * allwinner,sun6i-a31-drc
     * allwinner,sun6i-a31s-drc
     * allwinner,sun8i-a33-drc
+    * allwinner,sun9i-a80-drc
   - reg: base address and size of the memory-mapped region.
   - interrupts: interrupt associated to this IP
   - clocks: phandles to the clocks feeding the DRC
@@ -227,6 +228,7 @@ Required properties:
     * allwinner,sun6i-a31-display-backend
     * allwinner,sun7i-a20-display-backend
     * allwinner,sun8i-a33-display-backend
+    * allwinner,sun9i-a80-display-backend
   - reg: base address and size of the memory-mapped region.
   - interrupts: interrupt associated to this IP
   - clocks: phandles to the clocks feeding the frontend and backend
@@ -283,6 +285,7 @@ Required properties:
     * allwinner,sun6i-a31-display-frontend
     * allwinner,sun7i-a20-display-frontend
     * allwinner,sun8i-a33-display-frontend
+    * allwinner,sun9i-a80-display-frontend
   - reg: base address and size of the memory-mapped region.
   - interrupts: interrupt associated to this IP
   - clocks: phandles to the clocks feeding the frontend and backend
@@ -339,6 +342,7 @@ Required properties:
     * allwinner,sun8i-a83t-display-engine
     * allwinner,sun8i-h3-display-engine
     * allwinner,sun8i-v3s-display-engine
+    * allwinner,sun9i-a80-display-engine
 
   - allwinner,pipelines: list of phandle to the display engine
     frontends (DE 1.0) or mixers (DE 2.0) available.