dt-bindings: devfreq: event: rockchip,dfi: Add rk3568 support

This adds the rockchip,rk3568-dfi compatible to the binding. Make clocks
optional for this SoC as the RK3568 doesn't have a kernel controllable
PCLK.

Link: https://lore.kernel.org/all/20231018061714.3553817-22-s.hauer@pengutronix.de/
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

Documentation/devicetree/bindings/devfreq/event/rockchip,dfi.yaml

@@ -13,6 +13,7 @@ properties:
   compatible:
     enum:
       - rockchip,rk3399-dfi
+      - rockchip,rk3568-dfi
 
   clocks:
     maxItems: 1
@@ -34,11 +35,21 @@ properties:
 
 required:
   - compatible
-  - clocks
-  - clock-names
   - interrupts
   - reg
 
+if:
+  properties:
+    compatible:
+      contains:
+        enum:
+          - rockchip,rk3399-dfi
+
+then:
+  required:
+    - clocks
+    - clock-names
+
 additionalProperties: false
 
 examples: