dt-bindings: rtc: microcrystal,rv3028: Allow to specify vdd-supply

In case the VDD supply voltage regulator of the RTC needs to be
specified explicitly, allow to set vdd-supply.

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260309085749.25747-2-frieder@fris.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Author: fschrempf

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

@@ -32,6 +32,8 @@ properties:
       - 9000
       - 15000
 
+  vdd-supply: true
+
 required:
   - compatible
   - reg