dt-bindings:iio:adc:motorola,cpcap-adc yaml conversion

Conversion from txt to yaml.
Slightly expanded example to give a bit more context.
Description lifted from the original driver commit.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20200909175946.395313-12-jic23@kernel.org

Documentation/devicetree/bindings/iio/adc/cpcap-adc.txt

-Motorola CPCAP PMIC ADC binding
-
-Required properties:
-- compatible: Should be "motorola,cpcap-adc" or "motorola,mapphone-cpcap-adc"
-- interrupts: The interrupt number for the ADC device
-- interrupt-names: Should be "adcdone"
-- #io-channel-cells: Number of cells in an IIO specifier
-
-Example:
-
-cpcap_adc: adc {
-	compatible = "motorola,mapphone-cpcap-adc";
-	interrupt-parent = <&cpcap>;
-	interrupts = <8 IRQ_TYPE_NONE>;
-	interrupt-names = "adcdone";
-	#io-channel-cells = <1>;
-};

Documentation/devicetree/bindings/iio/adc/motorola,cpcap-adc.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/motorola,cpcap-adc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Motorola CPCAP PMIC ADC binding
+
+maintainers:
+  - Tony Lindgren <tony@atomide.com>
+
+description:
+  On Motorola phones like droid 4 there is a custom CPCAP PMIC. This PMIC
+  has ADCs that are used for battery charging and USB PHY VBUS and ID pin
+  detection.
+
+properties:
+  compatible:
+    enum:
+      - motorola,cpcap-adc
+      - motorola,mapphone-cpcap-adc
+
+  interrupts:
+    maxItems: 1
+
+  interrupt-names:
+    const: adcdone
+
+  "#io-channel-cells":
+    const: 1
+
+required:
+  - compatible
+  - interrupts
+  - "#io-channel-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    pmic {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        adc {
+            compatible = "motorola,mapphone-cpcap-adc";
+            interrupt-parent = <&cpcap>;
+            interrupts = <8 IRQ_TYPE_NONE>;
+            interrupt-names = "adcdone";
+            #io-channel-cells = <1>;
+        };
+    };
+...