dt-bindings: riscv: Add SOPHGO Huashan Pi board compatibles

Document the compatible strings for the SOPHGO Huashan Pi board which
uses the SOPHGO CV1812H SoC.

Signed-off-by: Inochi Amaoto <inochiama@outlook.com>
Link: https://en.sophgo.com/product/introduce/huashan.html
Link: https://en.sophgo.com/product/introduce/cv181xH.html
Acked-by: Chen Wang <unicorn_wang@outlook.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>

Documentation/devicetree/bindings/riscv/sophgo.yaml

@@ -22,6 +22,10 @@ properties:
           - enum:
               - milkv,duo
           - const: sophgo,cv1800b
+      - items:
+          - enum:
+              - sophgo,huashan-pi
+          - const: sophgo,cv1812h
       - items:
           - enum:
               - milkv,pioneer