dt-bindings: Add doc for Fastrhino R66S / R68S

Add devicetree binding documentation for the
Lunzn Fastrhino R66S and R68S boards.
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Tianling Shen <cnsztl@gmail.com>
Link: https://lore.kernel.org/r/20230506061108.17658-1-cnsztl@gmail.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

Documentation/devicetree/bindings/arm/rockchip.yaml

@@ -562,6 +562,13 @@ properties:
           - const: leez,p710
           - const: rockchip,rk3399
 
+      - description: Lunzn FastRhino R66S / R68S
+        items:
+          - enum:
+              - lunzn,fastrhino-r66s
+              - lunzn,fastrhino-r68s
+          - const: rockchip,rk3568
+
       - description: mqmaker MiQi
         items:
           - const: mqmaker,miqi

Documentation/devicetree/bindings/vendor-prefixes.yaml

@@ -781,6 +781,8 @@ patternProperties:
     description: Nanjing Loongmasses Ltd.
   "^lsi,.*":
     description: LSI Corp. (LSI Logic)
+  "^lunzn,.*":
+    description: Shenzhen Lunzn Technology Co., Ltd.
   "^lwn,.*":
     description: Liebherr-Werk Nenzing GmbH
   "^lxa,.*":