dt-bindings: mfd: ti,twl: Add clock provider properties

Since these devices provide clock outputs, add the corresponding
property.
Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230916100515.1650336-3-andreas@kemnade.infoSigned-off-by: Lee Jones <lee@kernel.org>

Documentation/devicetree/bindings/mfd/ti,twl.yaml

@@ -37,6 +37,9 @@ properties:
   "#interrupt-cells":
     const: 1
 
+  "#clock-cells":
+    const: 1
+
 additionalProperties: false
 
 required: