dt-bindings: power: supply: pm8941-coincell: Convert to DT schema format

Convert the binding to DT schema format.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/power/supply/qcom,coincell-charger.txt

-Qualcomm Coincell Charger:
-
-The hardware block controls charging for a coincell or capacitor that is
-used to provide power backup for certain features of the power management
-IC (PMIC)
-
-- compatible:
-	Usage: required
-	Value type: <string>
-	Definition: must be: "qcom,pm8941-coincell"
-
-- reg:
-	Usage: required
-	Value type: <u32>
-	Definition: base address of the coincell charger registers
-
-- qcom,rset-ohms:
-	Usage: required
-	Value type: <u32>
-	Definition: resistance (in ohms) for current-limiting resistor
-		must be one of: 800, 1200, 1700, 2100
-
-- qcom,vset-millivolts:
-	Usage: required
-	Value type: <u32>
-	Definition: voltage (in millivolts) to apply for charging
-		must be one of: 2500, 3000, 3100, 3200
-
-- qcom,charger-disable:
-	Usage: optional
-	Value type: <boolean>
-	Definition: defining this property disables charging
-
-This charger is a sub-node of one of the 8941 PMIC blocks, and is specified
-as a child node in DTS of that node.  See ../mfd/qcom,spmi-pmic.txt and
-../mfd/qcom-pm8xxx.txt
-
-Example:
-
-	pm8941@0 {
-		coincell@2800 {
-			compatible = "qcom,pm8941-coincell";
-			reg = <0x2800>;
-
-			qcom,rset-ohms = <2100>;
-			qcom,vset-millivolts = <3000>;
-		};
-	};

Documentation/devicetree/bindings/power/supply/qcom,pm8941-coincell.yaml

+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/supply/qcom,pm8941-coincell.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Coincell Charger
+
+description: |
+  The hardware block controls charging for a coincell or capacitor that is
+  used to provide power backup for certain features of the power management
+  IC (PMIC)
+
+maintainers:
+  - Sebastian Reichel <sre@kernel.org>
+
+properties:
+  compatible:
+    const: qcom,pm8941-coincell
+
+  reg:
+    maxItems: 1
+
+  qcom,rset-ohms:
+    description: resistance (in ohms) for current-limiting resistor
+    enum: [ 800, 1200, 1700, 2100 ]
+
+  qcom,vset-millivolts:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: voltage (in millivolts) to apply for charging
+    enum: [ 2500, 3000, 3100, 3200 ]
+
+  qcom,charger-disable:
+    type: boolean
+    description: defining this property disables charging
+
+required:
+  - compatible
+  - reg
+  - qcom,rset-ohms
+  - qcom,vset-millivolts
+
+additionalProperties: false
+
+examples:
+  - |
+    pmic {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      charger@2800 {
+        compatible = "qcom,pm8941-coincell";
+        reg = <0x2800>;
+        qcom,rset-ohms = <2100>;
+        qcom,vset-millivolts = <3000>;
+      };
+    };