dt-bindings: rtc: pcf8523: Convert to YAML

Convert the PCF8523 bindings from text format to YAML.

The YAML format is preferred as it allows validation.
Signed-off-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230905220826.79901-1-festevam@gmail.comSigned-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Documentation/devicetree/bindings/rtc/nxp,pcf8523.txt

-* NXP PCF8523 Real Time Clock
-
-Required properties:
-- compatible: Should contain "nxp,pcf8523".
-- reg: I2C address for chip.
-
-Optional property:
-- quartz-load-femtofarads: The capacitive load of the quartz(x-tal),
-  expressed in femto Farad (fF). Valid values are 7000 and 12500.
-  Default value (if no value is specified) is 12500fF.
-
-Example:
-
-pcf8523: rtc@68 {
-	compatible = "nxp,pcf8523";
-	reg = <0x68>;
-	quartz-load-femtofarads = <7000>;
-};

Documentation/devicetree/bindings/rtc/nxp,pcf8523.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/nxp,pcf8523.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP PCF8523 Real Time Clock
+
+maintainers:
+  - Sam Ravnborg <sam@ravnborg.org>
+
+allOf:
+  - $ref: rtc.yaml#
+
+properties:
+  compatible:
+    const: nxp,pcf8523
+
+  reg:
+    maxItems: 1
+
+  quartz-load-femtofarads:
+    description:
+      The capacitive load of the crystal, expressed in femto Farad (fF).
+    enum: [ 7000, 12500 ]
+    default: 12500
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        rtc@68 {
+            compatible = "nxp,pcf8523";
+            reg = <0x68>;
+            quartz-load-femtofarads = <7000>;
+        };
+    };