dt-bindings: rtc: max31335: Add max31331 support

Added DT compatible string for MAX31331.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: PavithraUdayakumar-adi <pavithra.u@analog.com>
Link: https://lore.kernel.org/r/20250217-add_support_max31331_fix_8-v1-1-16ebcfc02336@analog.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Author: PavithraUdayakumar-adi

Documentation/devicetree/bindings/rtc/adi,max31335.yaml

@@ -18,7 +18,9 @@ allOf:
 
 properties:
   compatible:
-    const: adi,max31335
+    enum:
+      - adi,max31331
+      - adi,max31335
 
   reg:
     maxItems: 1