dt-bindings: input: gpio-beeper: Convert to yaml schema

Convert the bindings from plain text to yaml schema.
Signed-off-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/20221120012135.2085631-1-festevam@gmail.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Documentation/devicetree/bindings/input/gpio-beeper.txt

-* GPIO beeper device tree bindings
-
-Register a beeper connected to GPIO pin.
-
-Required properties:
-- compatible:	Should be "gpio-beeper".
-- gpios:	From common gpio binding; gpio connection to beeper enable pin.
-
-Example:
-	beeper: beeper {
-		compatible = "gpio-beeper";
-		gpios = <&gpio3 23 GPIO_ACTIVE_HIGH>;
-	};

Documentation/devicetree/bindings/input/gpio-beeper.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/gpio-beeper.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: GPIO controlled beeper
+
+maintainers:
+  - Fabio Estevam <festevam@denx.de>
+
+properties:
+  compatible:
+    const: gpio-beeper
+
+  gpios:
+    maxItems: 1
+    description:
+      GPIO that drives the beeper.
+
+required:
+  - compatible
+  - gpios
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    beeper {
+        compatible = "gpio-beeper";
+        gpios = <&gpio3 23 GPIO_ACTIVE_HIGH>;
+    };