dt-bindings: input: touchscreen: st1232: Convert to json-schema

Convert the Sitronix st1232/st1633 touchscreen controller Device Tree
binding documentation to json-schema.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Martin Kepplinger <martink@posteo.de>
Link: https://lore.kernel.org/r/fbba650cff07780c28ad6dd8dbef5cc1451b7762.1623418065.git.geert+renesas@glider.beSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Documentation/devicetree/bindings/input/touchscreen/sitronix,st1232.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/touchscreen/sitronix,st1232.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Sitronix st1232 or st1633 touchscreen controller
+
+maintainers:
+  - Bastian Hecht <hechtb@gmail.com>
+
+allOf:
+  - $ref: touchscreen.yaml#
+
+properties:
+  compatible:
+    enum:
+      - sitronix,st1232
+      - sitronix,st1633
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  gpios:
+    description: A phandle to the reset GPIO
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    i2c {
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            touchscreen@55 {
+                    compatible = "sitronix,st1232";
+                    reg = <0x55>;
+                    interrupts = <2 0>;
+                    gpios = <&gpio1 166 0>;
+            };
+    };

Documentation/devicetree/bindings/input/touchscreen/sitronix-st1232.txt

-* Sitronix st1232 or st1633 touchscreen controller
-
-Required properties:
-- compatible: must contain one of
-  * "sitronix,st1232"
-  * "sitronix,st1633"
-- reg: I2C address of the chip
-- interrupts: interrupt to which the chip is connected
-
-Optional properties:
-- gpios: a phandle to the reset GPIO
-
-For additional optional properties see: touchscreen.txt
-
-Example:
-
-	i2c@00000000 {
-		/* ... */
-
-		touchscreen@55 {
-			compatible = "sitronix,st1232";
-			reg = <0x55>;
-			interrupts = <2 0>;
-			gpios = <&gpio1 166 0>;
-		};
-
-		/* ... */
-	};