dt-bindings: rtc: sc2731: Add compatible for SC2730

The RTC block found in the SC2730 PMIC is compatible with the one found
in the SC2731 PMIC.

Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Otto Pflüger <otto.pflueger@abscue.de>
Link: https://patch.msgid.link/20260329-sc27xx-mfd-cells-v3-1-9158dee41f74@abscue.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Author: affenull2345

Documentation/devicetree/bindings/rtc/sprd,sc2731-rtc.yaml

@@ -13,7 +13,12 @@ maintainers:
 
 properties:
   compatible:
-    const: sprd,sc2731-rtc
+    oneOf:
+      - items:
+          - enum:
+              - sprd,sc2730-rtc
+          - const: sprd,sc2731-rtc
+      - const: sprd,sc2731-rtc
 
   reg:
     maxItems: 1