dt-bindings:iio:humidity:hdc100x Drop separate doc + add to trivial-devices

Very simple binding for this i2c device with no properties beyond
reg and compatible.  Hence doesn't need it's own document.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Matt Ranostay <matt.ranostay@konsulko.com>
Link: https://lore.kernel.org/r/20201031134110.724233-2-jic23@kernel.org

Documentation/devicetree/bindings/iio/humidity/hdc100x.txt

@@ -1,17 +0,0 @@
-* HDC100x temperature + humidity sensors
-
-Required properties:
-  - compatible: Should contain one of the following:
-	ti,hdc1000
-	ti,hdc1008
-	ti,hdc1010
-	ti,hdc1050
-	ti,hdc1080
-  - reg: i2c address of the sensor
-
-Example:
-
-hdc100x@40 {
-	compatible = "ti,hdc1000";
-	reg = <0x40>;
-};

Documentation/devicetree/bindings/trivial-devices.yaml

@@ -352,6 +352,16 @@ properties:
           - ti,ads7830
             # Temperature Monitoring and Fan Control
           - ti,amc6821
+            # Temperature and humidity sensor with i2c interface
+          - ti,hdc1000
+            # Temperature and humidity sensor with i2c interface
+          - ti,hdc1008
+            # Temperature and humidity sensor with i2c interface
+          - ti,hdc1010
+            # Temperature and humidity sensor with i2c interface
+          - ti,hdc1050
+            # Temperature and humidity sensor with i2c interface
+          - ti,hdc1080
             # Temperature sensor with 2-wire interface
           - ti,lm73
             # Temperature sensor with integrated fan control