Document the Graperain G3568 v2, which is a development board based on
the Rockchip RK3568 SoC.

Graperain G3568 series also have an SBC series with the suffix "box".

Graperain G3568 v2 belongs to development board series, not SBC series.

Link: https://www.graperain.cn/RK3568/RK3568-Development/ (China)
Link: https://www.graperain.com/ARM-Embedded-RK3568-Development-Board/ (Global)
Link: https://image.chukouplus.com/upload/C_153/product_file/20211022/6daddec9e400458816dd4c57ba807fc3.pdf

Signed-off-by: Coia Prant <redacted>
Acked-by: Krzysztof Kozlowski <redacted>
---
 Documentation/devicetree/bindings/arm/rockchip.yaml | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/rockchip.yaml b/Documentation/devicetree/bindings/arm/rockchip.yaml
index 1a9dde18626d0..9eb2f66ba3856 100644
--- a/Documentation/devicetree/bindings/arm/rockchip.yaml
+++ b/Documentation/devicetree/bindings/arm/rockchip.yaml

@@ -684,6 +684,12 @@ properties:
           - const: google,veyron
           - const: rockchip,rk3288
 
+      - description: Graperain G3568 series board
+        items:
+          - enum:
+              - graperain,g3568-v2
+          - const: rockchip,rk3568
+
       - description: H96 Max V58 TV Box
         items:
           - const: haochuangyi,h96-max-v58

-- 
2.47.3