dt-bindings:iio:adc:cosmic,10001-adc yaml conversion

I don't really know much about this one, hence the binding is
a simple conversion of what was in the txt file.

Note that I have taken on maintenance of this binding as I don't
have a recent address for Phani Movva.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200909175946.395313-14-jic23@kernel.org

Documentation/devicetree/bindings/iio/adc/cc10001_adc.txt

-* Cosmic Circuits - Analog to Digital Converter (CC-10001-ADC)
-
-Required properties:
-  - compatible: Should be "cosmic,10001-adc"
-  - reg: Should contain adc registers location and length.
-  - clock-names: Should contain "adc".
-  - clocks: Should contain a clock specifier for each entry in clock-names
-  - vref-supply: The regulator supply ADC reference voltage.
-
-Optional properties:
-  - adc-reserved-channels: Bitmask of reserved channels,
-    i.e. channels that cannot be used by the OS.
-
-Example:
-adc: adc@18101600 {
-	compatible = "cosmic,10001-adc";
-	reg = <0x18101600 0x24>;
-	adc-reserved-channels = <0x2>;
-	clocks = <&adc_clk>;
-	clock-names = "adc";
-	vref-supply = <&reg_1v8>;
-};

Documentation/devicetree/bindings/iio/adc/cosmic,10001-adc.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/cosmic,10001-adc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Cosmic Circuits CC-10001 ADC
+
+maintainers:
+  - Jonathan Cameron <jic23@kernel.org>
+
+description:
+  Cosmic Circuits 10001 10-bit ADC device.
+
+properties:
+  compatible:
+    const: cosmic,10001-adc
+
+  reg:
+    maxItems: 1
+
+  adc-reserved-channels:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+       Bitmask of reserved channels, i.e. channels that cannot be
+       used by the OS.
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    const: adc
+
+  vref-supply: true
+
+  "#io-channel-cells":
+    const: 1
+
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - vref-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    adc@18101600 {
+        compatible = "cosmic,10001-adc";
+        reg = <0x18101600 0x24>;
+        adc-reserved-channels = <0x2>;
+        clocks = <&adc_clk>;
+        clock-names = "adc";
+        vref-supply = <&reg_1v8>;
+    };
+...