dt-bindings: power: reset: qcom,pshold: convert to dtschema

Convert the Qualcomm Power Supply Hold Reset bindings to DT schema.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

Documentation/devicetree/bindings/power/reset/msm-poweroff.txt

-MSM Restart Driver
-
-A power supply hold (ps-hold) bit is set to power the msm chipsets.
-Clearing that bit allows us to restart/poweroff. The difference
-between poweroff and restart is determined by unique power manager IC
-settings.
-
-Required Properties:
--compatible: "qcom,pshold"
--reg: Specifies the physical address of the ps-hold register
-
-Example:
-
-	restart@fc4ab000 {
-		compatible = "qcom,pshold";
-		reg = <0xfc4ab000 0x4>;
-	};

Documentation/devicetree/bindings/power/reset/qcom,pshold.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/reset/qcom,pshold.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm SoC restart and power off
+
+maintainers:
+  - Bjorn Andersson <bjorn.andersson@linaro.org>
+
+description:
+  A power supply hold (ps-hold) bit is set to power the Qualcomm chipsets.
+  Clearing that bit allows us to restart/power off. The difference between
+  power off and restart is determined by unique power manager IC settings.
+
+properties:
+  compatible:
+    const: qcom,pshold
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    reset-controller@fc4ab000 {
+        compatible = "qcom,pshold";
+        reg = <0xfc4ab000 0x4>;
+    };