dt-bindings: arm: sunxi: document Anbernic RG35XX handheld gaming device variants

RG35XX 2024: Base version with Allwinner H700
RG35XX Plus: Adds Wifi/BT
RG35XX H: Adds second USB port and analog sticks to -Plus in horizontal form factor

Use three separate device descriptions rather than enum as per existing sunxi binding style.
Signed-off-by: Ryan Walklin <ryan@testtoast.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240427110225.727472-4-ryan@testtoast.comSigned-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>

Documentation/devicetree/bindings/arm/sunxi.yaml

@@ -56,6 +56,21 @@ properties:
           - const: anbernic,rg-nano
           - const: allwinner,sun8i-v3s
 
+      - description: Anbernic RG35XX (2024)
+      - items:
+          - const: anbernic,rg35xx-2024
+          - const: allwinner,sun50i-h700
+
+      - description: Anbernic RG35XX Plus
+      - items:
+          - const: anbernic,rg35xx-plus
+          - const: allwinner,sun50i-h700
+
+      - description: Anbernic RG35XX H
+      - items:
+          - const: anbernic,rg35xx-h
+          - const: allwinner,sun50i-h700
+
       - description: Amarula A64 Relic
         items:
           - const: amarula,a64-relic