dt-bindings: arm: sunxi: Add Anbernic RG35XXSP

Add the Anbernic RG35XXSP variant device.

The Anbernic RG35XXSP is almost identical to the RG35XX-Plus, but in a
clamshell form-factor with an external RTC and a lid switch.

Signed-off-by: Chris Morgan <[e-mail]>
Acked-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Chen-Yu Tsai <[e-mail]>

Documentation/devicetree/bindings/arm/sunxi.yaml

···
           - const: anbernic,rg35xx-2024
           - const: allwinner,sun50i-h700
 
+      - description: Anbernic RG35XX H
+        items:
+          - const: anbernic,rg35xx-h
+          - const: allwinner,sun50i-h700
+
       - description: Anbernic RG35XX Plus
         items:
           - const: anbernic,rg35xx-plus
           - const: allwinner,sun50i-h700
 
-      - description: Anbernic RG35XX H
+      - description: Anbernic RG35XX SP
         items:
-          - const: anbernic,rg35xx-h
+          - const: anbernic,rg35xx-sp
           - const: allwinner,sun50i-h700
 
       - description: Amarula A64 Relic