dt-bindings: reset: Convert snps,dw-reset to DT schema

Convert the Synopsys Designware Reset Controller binding to schema. It
is a straight forward conversion.

Signed-off-by: Rob Herring (Arm) <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Philipp Zabel <[e-mail]>

Documentation/devicetree/bindings/reset/snps,dw-reset.txt

···
-Synopsys DesignWare Reset controller
-=======================================
-
-Please also refer to reset.txt in this directory for common reset
-controller binding usage.
-
-Required properties:
-
-- compatible: should be one of the following.
-	"snps,dw-high-reset" - for active high configuration
-	"snps,dw-low-reset" - for active low configuration
-
-- reg: physical base address of the controller and length of memory mapped
-	region.
-
-- #reset-cells: must be 1.
-
-example:
-
-	dw_rst_1: reset-controller@0000 {
-		compatible = "snps,dw-high-reset";
-		reg = <0x0000 0x4>;
-		#reset-cells = <1>;
-	};
-
-	dw_rst_2: reset-controller@1000 {
-		compatible = "snps,dw-low-reset";
-		reg = <0x1000 0x8>;
-		#reset-cells = <1>;
-	};

Documentation/devicetree/bindings/reset/snps,dw-reset.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reset/snps,dw-reset.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Synopsys DesignWare Reset controller
+
+maintainers:
+  - Philipp Zabel <[e-mail]>
+
+properties:
+  compatible:
+    enum:
+      - snps,dw-high-reset
+      - snps,dw-low-reset
+
+  reg:
+    maxItems: 1
+
+  '#reset-cells':
+    const: 1
+
+  reset-controller: true
+
+required:
+  - compatible
+  - reg
+  - '#reset-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    reset-controller@0 {
+        compatible = "snps,dw-high-reset";
+        reg = <0x0000 0x4>;
+        #reset-cells = <1>;
+    };