dt-bindings: watchdog: xlnx,versal-wwdt: Add optional power-domains property

AMD/Xilinx Versal Window Watchdog Timer has its own power domain, so add
an optional property to describe it.

Signed-off-by: Harini T <harini.t@amd.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/20250130120233.742879-1-harini.t@amd.com

Author: Harini T

Documentation/devicetree/bindings/watchdog/xlnx,versal-wwdt.yaml

@@ -32,6 +32,9 @@ properties:
   clocks:
     maxItems: 1
 
+  power-domains:
+    maxItems: 1
+
 required:
   - compatible
   - reg