dt-bindings: Add MAX31730 as trivial device

Maxim MAX31730 is a 3-Channel Remote Temperature Sensor.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/trivial-devices.yaml

@@ -132,6 +132,8 @@ properties:
           - maxim,max6621
             # 9-Bit/12-Bit Temperature Sensors with I²C-Compatible Serial Interface
           - maxim,max6625
+            # 3-Channel Remote Temperature Sensor
+          - maxim,max31730
             # mCube 3-axis 8-bit digital accelerometer
           - mcube,mc3230
             # MEMSIC 2-axis 8-bit digital accelerometer