dt-bindings:iio:magnetometer:honeywell,hmc5843: txt to yaml format conversion

Mostly a straight conversion, but the txt file had an oddity.
It documented a gpios property for what appeared to be in interrupt line.
There are mainline dts that have this as interrupts, so I've converted
it to that.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Neil Brown <neilb@suse.de>
Link: https://lore.kernel.org/r/20201031184854.745828-27-jic23@kernel.org

Documentation/devicetree/bindings/iio/magnetometer/hmc5843.txt

-* Honeywell HMC5843 magnetometer sensor
-
-Required properties:
-
-  - compatible : should be "honeywell,hmc5843"
-  Other models which are supported with driver are:
-	"honeywell,hmc5883"
-	"honeywell,hmc5883l"
-	"honeywell,hmc5983"
-  - reg : the I2C address of the magnetometer - typically 0x1e
-
-Optional properties:
-
-  - gpios : should be device tree identifier of the magnetometer DRDY pin
-
-Example:
-
-hmc5843@1e {
-        compatible = "honeywell,hmc5843"
-        reg = <0x1e>;
-};

Documentation/devicetree/bindings/iio/magnetometer/honeywell,hmc5843.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/magnetometer/honeywell,hmc5843.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Honeywell HMC5843 magnetometer sensor
+
+maintainers:
+  - Neil Brown <neilb@suse.de>
+
+properties:
+  compatible:
+    enum:
+      - honeywell,hmc5843
+      - honeywell,hmc5883
+      - honeywell,hmc5883l
+      - honeywell,hmc5983
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+additionalProperties: false
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        magnetometer@1e {
+            compatible = "honeywell,hmc5843";
+            reg = <0x1e>;
+        };
+    };
+...