dt-bindings: arm: sunxi: add ICnova A20 ADB4006 binding

Document board compatible names for In-Circuit ICnova A20 ADB4006
development board.
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Ludwig Kormann <ludwig.kormann@ict42.de>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20230510111528.2155582-2-ludwig.kormann@ict42.deSigned-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>

Documentation/devicetree/bindings/arm/sunxi.yaml

@@ -305,6 +305,12 @@ properties:
           - const: allwinner,i12-tvbox
           - const: allwinner,sun7i-a20
 
+      - description: ICnova A20 ADB4006
+        items:
+          - const: incircuit,icnova-a20-adb4006
+          - const: incircuit,icnova-a20
+          - const: allwinner,sun7i-a20
+
       - description: ICNova A20 SWAC
         items:
           - const: incircuit,icnova-a20-swac