dt-bindings:iio:adc:ti,twl4030-madc yaml conversion

Conversion from txt to yaml as part of a general move of IIO bindings
to the new format.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Sebastian Reichel <sre@kernel.org>
Link: https://lore.kernel.org/r/20200909175946.395313-3-jic23@kernel.org

Documentation/devicetree/bindings/iio/adc/ti,twl4030-madc.yaml

@@ -0,0 +1,48 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/ti,twl4030-madc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MADC subsystem in the TWL4030 power module
+
+maintainers:
+  - Sebastian Reichel <sre@kernel.org>
+
+description:
+  The MADC subsystem in the TWL4030 consists of a 10-bit ADC
+  combined with a 16-input analog multiplexer.
+
+properties:
+  compatible:
+    const: ti,twl4030-madc
+
+  interrupts:
+    maxItems: 1
+
+  ti,system-uses-second-madc-irq:
+    type: boolean
+    description:
+      Set if the second madc irq register should be used, which is intended
+      to be used  by Co-Processors (e.g. a modem).
+
+  "#io-channel-cells":
+    const: 1
+
+required:
+  - compatible
+  - interrupts
+  - "#io-channel-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    twl {
+        madc {
+            compatible = "ti,twl4030-madc";
+            interrupts = <3>;
+            #io-channel-cells = <1>;
+        };
+    };
+...