dt-bindings: rtc: isl12022: add #clock-cells property

The isl12022 has a dual-purpose irq/f_out pin, which can either be
used as an interrupt or clock output.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230615105826.411953-8-linux@rasmusvillemoes.dk
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Author: Villemoes

Documentation/devicetree/bindings/rtc/intersil,isl12022.yaml

@@ -19,6 +19,9 @@ properties:
   interrupts:
     maxItems: 1
 
+  '#clock-cells':
+    const: 0
+
   isil,battery-trip-levels-microvolt:
     description:
       The battery voltages at which the first alarm and second alarm
@@ -33,6 +36,13 @@ required:
 
 allOf:
   - $ref: rtc.yaml#
+  # If #clock-cells is present, interrupts must not be present
+  - if:
+      required:
+        - '#clock-cells'
+    then:
+      properties:
+        interrupts: false
 
 unevaluatedProperties: false