regulator: dt-bindings: fcs,fan53555: Add support for RK860X

Add compatibles to support Rockchip RK860X regulators.

RK8600/RK8601 are pretty similar to the FAN53555 regulators, while
RK8602/RK8603 are a bit different, having a wider voltage selection
range.
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230406194158.963352-2-cristian.ciocaltea@collabora.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/regulator/fcs,fan53555.yaml

@@ -14,12 +14,21 @@ allOf:
 
 properties:
   compatible:
-    enum:
-      - fcs,fan53555
-      - fcs,fan53526
-      - silergy,syr827
-      - silergy,syr828
-      - tcs,tcs4525
+    oneOf:
+      - enum:
+          - fcs,fan53555
+          - fcs,fan53526
+          - rockchip,rk8600
+          - rockchip,rk8602
+          - silergy,syr827
+          - silergy,syr828
+          - tcs,tcs4525
+      - items:
+          - const: rockchip,rk8601
+          - const: rockchip,rk8600
+      - items:
+          - const: rockchip,rk8603
+          - const: rockchip,rk8602
 
   reg:
     maxItems: 1