dt-bindings: mmc: convert orion-sdio to JSON schema

Convert the orion-sdio binding to JSON schema.
Signed-off-by: NChris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: NKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220419024611.1327525-4-chris.packham@alliedtelesis.co.nzSigned-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Documentation/devicetree/bindings/mmc/marvell,orion-sdio.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mmc/marvell,orion-sdio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Marvell orion-sdio controller
+
+maintainers:
+  - Nicolas Pitre <nico@fluxnic.net>
+  - Ulf Hansson <ulf.hansson@linaro.org>
+
+allOf:
+  - $ref: mmc-controller.yaml#
+
+properties:
+  compatible:
+    const: marvell,orion-sdio
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    mmc@d00d4000 {
+      compatible = "marvell,orion-sdio";
+      reg = <0xd00d4000 0x200>;
+      interrupts = <54>;
+      clocks = <&gateclk 17>;
+    };

Documentation/devicetree/bindings/mmc/orion-sdio.txt

-* Marvell orion-sdio controller
-
-This file documents differences between the core properties in mmc.txt
-and the properties used by the orion-sdio driver.
-
-- compatible: Should be "marvell,orion-sdio"
-- clocks: reference to the clock of the SDIO interface
-
-Example:
-
-	mvsdio@d00d4000 {
-		compatible = "marvell,orion-sdio";
-		reg = <0xd00d4000 0x200>;
-		interrupts = <54>;
-		clocks = <&gateclk 17>;
-	};