dt-bindings: dma: Convert UniPhier MIO DMA controller to json-schema

Convert the UniPhier MIO (Media I/O) DMA controller binding to DT
schema format.

While I was here, I added the resets property.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/dma/socionext,uniphier-mio-dmac.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/dma/socionext,uniphier-mio-dmac.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: UniPhier Media IO DMA controller
+
+description: |
+  This works as an external DMA engine for SD/eMMC controllers etc.
+  found in UniPhier LD4, Pro4, sLD8 SoCs.
+
+maintainers:
+  - Masahiro Yamada <yamada.masahiro@socionext.com>
+
+allOf:
+  - $ref: "dma-controller.yaml#"
+
+properties:
+  compatible:
+    const: socionext,uniphier-mio-dmac
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    description: |
+      A list of interrupt specifiers associated with the DMA channels.
+      The number of interrupt lines is SoC-dependent.
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  '#dma-cells':
+    description: The single cell represents the channel index.
+    const: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - '#dma-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    // In the example below, "interrupts = <0 68 4>, <0 68 4>, ..." is not a
+    // typo. The first two channels share a single interrupt line.
+
+    dmac: dma-controller@5a000000 {
+        compatible = "socionext,uniphier-mio-dmac";
+        reg = <0x5a000000 0x1000>;
+        interrupts = <0 68 4>, <0 68 4>, <0 69 4>, <0 70 4>,
+                     <0 71 4>, <0 72 4>, <0 73 4>, <0 74 4>;
+        clocks = <&mio_clk 7>;
+        resets = <&mio_rst 7>;
+        #dma-cells = <1>;
+    };

Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt

-UniPhier Media IO DMA controller
-
-This works as an external DMA engine for SD/eMMC controllers etc.
-found in UniPhier LD4, Pro4, sLD8 SoCs.
-
-Required properties:
-- compatible: should be "socionext,uniphier-mio-dmac".
-- reg: offset and length of the register set for the device.
-- interrupts: a list of interrupt specifiers associated with the DMA channels.
-- clocks: a single clock specifier.
-- #dma-cells: should be <1>. The single cell represents the channel index.
-
-Example:
-	dmac: dma-controller@5a000000 {
-		compatible = "socionext,uniphier-mio-dmac";
-		reg = <0x5a000000 0x1000>;
-		interrupts = <0 68 4>, <0 68 4>, <0 69 4>, <0 70 4>,
-			     <0 71 4>, <0 72 4>, <0 73 4>, <0 74 4>;
-		clocks = <&mio_clk 7>;
-		#dma-cells = <1>;
-	};
-
-Note:
-In the example above, "interrupts = <0 68 4>, <0 68 4>, ..." is not a typo.
-The first two channels share a single interrupt line.