dt-bindings: rtc: digicolor-rtc: move to trivial-rtc

Convert existing binding to dtschema to support validation.

This device meets the requirements to be moved to trivial-rtc
(compatible, reg and a single interrupt).

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20240326-rtc-yaml-v3-3-caa430ecace7@gmail.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Author: javiercarrascocruz

Documentation/devicetree/bindings/rtc/digicolor-rtc.txt

@@ -24,6 +24,8 @@ properties:
       - abracon,abb5zes3
       # AB-RTCMC-32.768kHz-EOZ9: Real Time Clock/Calendar Module with I2C Interface
       - abracon,abeoz9
+      # Conexant Digicolor Real Time Clock Controller
+      - cnxt,cx92755-rtc
       # I2C, 32-Bit Binary Counter Watchdog RTC with Trickle Charger and Reset Input/Output
       - dallas,ds1374
       # Dallas DS1672 Real-time Clock