dt-bindings: extcon: usbc-cros-ec: convert extcon-usbc-cros-ec.txt to yaml format

convert the binding file extcon-usbc-cros-ec.txt to
yaml format extcon-usbc-cros-ec.yaml

This was tested and verified on ARM with:
make dt_binding_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/extcon/extcon-usbc-cros-ec.yaml
make dtbs_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/extcon/extcon-usbc-cros-ec.yaml
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

Documentation/devicetree/bindings/extcon/extcon-usbc-cros-ec.txt

-ChromeOS EC USB Type-C cable and accessories detection
-
-On ChromeOS systems with USB Type C ports, the ChromeOS Embedded Controller is
-able to detect the state of external accessories such as display adapters
-or USB devices when said accessories are attached or detached.
-
-The node for this device must be under a cros-ec node like google,cros-ec-spi
-or google,cros-ec-i2c.
-
-Required properties:
-- compatible:		Should be "google,extcon-usbc-cros-ec".
-- google,usb-port-id:	Specifies the USB port ID to use.
-
-Example:
-	cros-ec@0 {
-		compatible = "google,cros-ec-i2c";
-
-		...
-
-		extcon {
-			compatible = "google,extcon-usbc-cros-ec";
-			google,usb-port-id = <0>;
-		};
-	}

Documentation/devicetree/bindings/extcon/extcon-usbc-cros-ec.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/extcon/extcon-usbc-cros-ec.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ChromeOS EC USB Type-C cable and accessories detection
+
+maintainers:
+  - Benson Leung <bleung@chromium.org>
+  - Enric Balletbo i Serra <enric.balletbo@collabora.com>
+
+description: |
+  On ChromeOS systems with USB Type C ports, the ChromeOS Embedded Controller is
+  able to detect the state of external accessories such as display adapters
+  or USB devices when said accessories are attached or detached.
+  The node for this device must be under a cros-ec node like google,cros-ec-spi
+  or google,cros-ec-i2c.
+
+properties:
+  compatible:
+    const: google,extcon-usbc-cros-ec
+
+  google,usb-port-id:
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+    description: the port id
+    minimum: 0
+    maximum: 255
+
+required:
+  - compatible
+  - google,usb-port-id
+
+additionalProperties: false
+
+examples:
+  - |
+    spi0 {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        cros-ec@0 {
+            compatible = "google,cros-ec-spi";
+            reg = <0>;
+
+            usbc_extcon0: extcon0 {
+                compatible = "google,extcon-usbc-cros-ec";
+                google,usb-port-id = <0>;
+            };
+
+            usbc_extcon1: extcon1 {
+                compatible = "google,extcon-usbc-cros-ec";
+                google,usb-port-id = <1>;
+            };
+        };
+    };