dt-bindings: trivial-devices: Add sht2x sensors

Add sensirion,sht2x trivial sensors.

Signed-off-by: Kurt Borja <[e-mail]>
Acked-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Guenter Roeck <[e-mail]>

Documentation/devicetree/bindings/trivial-devices.yaml

···
             # Sensirion low power multi-pixel gas sensor with I2C interface
           - sensirion,sgpc3
             # Sensirion temperature & humidity sensor with I2C interface
+          - sensirion,sht20
+          - sensirion,sht21
+          - sensirion,sht25
           - sensirion,sht4x
             # Sensortek 3 axis accelerometer
           - sensortek,stk8312