dt-bindings:iio:gyro:invensense,mpu3050: txt to yaml format conversion.

Very similar to the mpu6050 binding.
Only unusual element is the i2c-gate section.
Example tweaked a little to include a real device behind the gate.

As Rob Herring suggested, dropped use of explicit i2c-gate yaml
binding in favour of just using the i2c-controller.yaml binding
directly.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201128173343.390165-4-jic23@kernel.org

Documentation/devicetree/bindings/iio/gyroscope/invensense,mpu3050.txt

-Invensense MPU-3050 Gyroscope device tree bindings
-
-Required properties:
-  - compatible : should be "invensense,mpu3050"
-  - reg : the I2C address of the sensor
-
-Optional properties:
-  - interrupts : interrupt mapping for the trigger interrupt from the
-    internal oscillator. The following IRQ modes are supported:
-    IRQ_TYPE_EDGE_RISING, IRQ_TYPE_EDGE_FALLING, IRQ_TYPE_LEVEL_HIGH and
-    IRQ_TYPE_LEVEL_LOW. The driver should detect and configure the hardware
-    for the desired interrupt type.
-  - vdd-supply : supply regulator for the main power voltage.
-  - vlogic-supply : supply regulator for the signal voltage.
-  - mount-matrix : see iio/mount-matrix.txt
-
-Optional subnodes:
-  - The MPU-3050 will pass through and forward the I2C signals from the
-    incoming I2C bus, alternatively drive traffic to a slave device (usually
-    an accelerometer) on its own initiative. Therefore is supports a subnode
-    i2c gate node. For details see: i2c/i2c-gate.txt
-
-Example:
-
-mpu3050@68 {
-	compatible = "invensense,mpu3050";
-	reg = <0x68>;
-	interrupt-parent = <&foo>;
-	interrupts = <12 IRQ_TYPE_EDGE_FALLING>;
-	vdd-supply = <&bar>;
-	vlogic-supply = <&baz>;
-
-	/* External I2C interface */
-	i2c-gate {
-		#address-cells = <1>;
-		#size-cells = <0>;
-
-		fnord@18 {
-			compatible = "fnord";
-			reg = <0x18>;
-			interrupt-parent = <&foo>;
-			interrupts = <13 IRQ_TYPE_EDGE_FALLING>;
-		};
-	};
-};

Documentation/devicetree/bindings/iio/gyroscope/invensense,mpu3050.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/gyroscope/invensense,mpu3050.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Invensense MPU-3050 Gyroscope
+
+maintainers:
+  - Linus Walleij <linus.walleij@linaro.org>
+
+properties:
+  compatible:
+    const: invensense,mpu3050
+
+  reg:
+    maxItems: 1
+
+  vdd-supply: true
+
+  vlogic-supply: true
+
+  interrupts:
+    minItems: 1
+    description:
+      Interrupt mapping for the trigger interrupt from the internal oscillator.
+
+  mount-matrix: true
+
+  i2c-gate:
+    $ref: /schemas/i2c/i2c-controller.yaml
+    unevaluatedProperties: false
+    description: |
+      The MPU-3050 will pass through and forward the I2C signals from the
+      incoming I2C bus, alternatively drive traffic to a slave device (usually
+      an accelerometer) on its own initiative. Therefore is supports an
+      i2c-gate subnode.
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        gyroscope@68 {
+            compatible = "invensense,mpu3050";
+            reg = <0x68>;
+            interrupt-parent = <&foo>;
+            interrupts = <12 IRQ_TYPE_EDGE_FALLING>;
+            vdd-supply = <&bar>;
+            vlogic-supply = <&baz>;
+
+            i2c-gate {
+                #address-cells = <1>;
+                #size-cells = <0>;
+
+                magnetometer@c {
+                    compatible = "ak,ak8975";
+                    reg = <0x0c>;
+                };
+            };
+        };
+    };
+...