dt-bindings: thermal: st,stm32: reference thermal-sensor schema

Device is a thermal sensor and it requires '#thermal-sensor-cells', so
reference the thermal-sensor.yaml to simplify it and bring the
common definition of '#thermal-sensor-cells' property.
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240705-dt-bindings-thermal-allof-v1-18-554061b52fbc@linaro.orgSigned-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Documentation/devicetree/bindings/thermal/st,stm32-thermal.yaml

@@ -9,6 +9,8 @@ title: STMicroelectronics STM32 digital thermal sensor (DTS)
 maintainers:
   - Pascal Paillet <p.paillet@foss.st.com>
 
+$ref: thermal-sensor.yaml#
+
 properties:
   compatible:
     const: st,stm32-thermal
@@ -30,14 +32,13 @@ properties:
     const: 0
 
 required:
-  - "#thermal-sensor-cells"
   - compatible
   - reg
   - interrupts
   - clocks
   - clock-names
 
-additionalProperties: false
+unevaluatedProperties: false
 
 examples:
   - |