Add devicetree bindings for the FriendlyElec CM3588 NAS board.

The CM3588 NAS by FriendlyElec pairs the CM3588 compute module, based on
the Rockchip RK3588 SoC, with the CM3588 NAS Kit carrier board.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Sebastian Kropatsch <seb-dev@mail.de>
---
 Documentation/devicetree/bindings/arm/rockchip.yaml | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/rockchip.yaml b/Documentation/devicetree/bindings/arm/rockchip.yaml
index 77469270b271..eca0a42eb384 100644
--- a/Documentation/devicetree/bindings/arm/rockchip.yaml
+++ b/Documentation/devicetree/bindings/arm/rockchip.yaml
@@ -248,6 +248,13 @@ properties:
           - const: friendlyarm,nanopc-t6
           - const: rockchip,rk3588
 
+      - description: FriendlyElec CM3588-based boards
+        items:
+          - enum:
+              - friendlyarm,cm3588-nas
+          - const: friendlyarm,cm3588
+          - const: rockchip,rk3588
+
       - description: GameForce Chi
         items:
           - const: gameforce,chi
-- 
2.43.0