dt-bindings: media: st: csi: add 'power-domains' property

STM32 CSI may be in a power domain which is the case for the STM32MP2x
based boards. Allow a single 'power-domains' entry for STM32 CSI.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20251219-stm32-mp2x-dcmipp-csi-power-domain-v1-1-a6edb2aa8154@foss.st.com
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

Author: Alain Volmat

Documentation/devicetree/bindings/media/st,stm32mp25-csi.yaml

@@ -46,6 +46,9 @@ properties:
     minItems: 1
     maxItems: 2
 
+  power-domains:
+    maxItems: 1
+
   ports:
     $ref: /schemas/graph.yaml#/properties/ports