dt-bindings: rtc: rx8900: Convert to YAML schema

Convert the Epson RX8900 DT bindings to YAML schema.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: kernel@dh-electronics.com
Cc: linux-rtc@vger.kernel.org
To: devicetree@vger.kernel.org
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210610150044.29792-1-marex@denx.de

Documentation/devicetree/bindings/rtc/epson,rx8900.txt

-Real Time Clock driver for:
-  - Epson RX8900
-  - Micro Crystal rv8803
-
-Required properties:
-- compatible: should be: "microcrystal,rv8803" or "epson,rx8900"
-- reg : the I2C address of the device for I2C
-
-Optional properties:
-- epson,vdet-disable : boolean, if present will disable voltage detector.
-  Should be set if no backup battery is used.
-- trickle-diode-disable : boolean, if present will disable internal trickle
-  charger diode
-
-Example:
-
-	rtc: rtc@32 {
-		compatible = "epson,rx8900"
-		reg = <0x32>;
-		epson,vdet-disable;
-		trickle-diode-disable;
-	};

Documentation/devicetree/bindings/rtc/epson,rx8900.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/epson,rx8900.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: EPSON RX8900 / Microcrystal RV8803 Real-Time Clock DT bindings
+
+maintainers:
+  - Marek Vasut <marex@denx.de>
+
+allOf:
+  - $ref: rtc.yaml#
+
+properties:
+  compatible:
+    enum:
+      - epson,rx8900
+      - microcrystal,rv8803
+
+  reg:
+    maxItems: 1
+
+  epson,vdet-disable:
+    type: boolean
+    description: |
+      Disable voltage detector. Should be set if no backup battery is used.
+
+  trickle-diode-disable: true
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        rtc@32 {
+            compatible = "epson,rx8900";
+            reg = <0x32>;
+            epson,vdet-disable;
+            trickle-diode-disable;
+        };
+    };