dt-bindings: rtc: microcrystal,rv3028: add #clock-cells property

RV3028 RTC has a clock out features, the clk out can be
controlled using clkout register, to consume the clock out
from rv3028 '#clock-cells' property is added.
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Karthikeyan Krishnasamy <karthikeyan@linumiz.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20240912142451.2952633-4-karthikeyan@linumiz.comSigned-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Documentation/devicetree/bindings/rtc/microcrystal,rv3028.yaml

@@ -22,6 +22,9 @@ properties:
   interrupts:
     maxItems: 1
 
+  "#clock-cells":
+    const: 0
+
   trickle-resistor-ohms:
     enum:
       - 3000