dt-bindings: net: convert mscc-miim to YAML format

Convert the mscc-miim device tree binding to the new YAML format.

The original binding don't mention if the interrupt property is optional
or not. But on the SparX-5 SoC, for example, the interrupt property isn't
used, thus in the new binding that property is optional. FWIW the driver
doesn't use interrupts at all.
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/mscc,miim.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/mscc,miim.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microsemi MII Management Controller (MIIM)
+
+maintainers:
+  - Alexandre Belloni <alexandre.belloni@bootlin.com>
+
+allOf:
+  - $ref: "mdio.yaml#"
+
+properties:
+  compatible:
+    enum:
+      - mscc,ocelot-miim
+      - microchip,lan966x-miim
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  reg:
+    items:
+      - description: base address
+      - description: associated reset register for internal PHYs
+    minItems: 1
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - "#address-cells"
+  - "#size-cells"
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    mdio@107009c {
+      compatible = "mscc,ocelot-miim";
+      reg = <0x107009c 0x36>, <0x10700f0 0x8>;
+      interrupts = <14>;
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      phy0: ethernet-phy@0 {
+        reg = <0>;
+      };
+    };

Documentation/devicetree/bindings/net/mscc-miim.txt

-Microsemi MII Management Controller (MIIM) / MDIO
-=================================================
-
-Properties:
-- compatible: must be "mscc,ocelot-miim" or "microchip,lan966x-miim"
-- reg: The base address of the MDIO bus controller register bank. Optionally, a
-  second register bank can be defined if there is an associated reset register
-  for internal PHYs
-- #address-cells: Must be <1>.
-- #size-cells: Must be <0>.  MDIO addresses have no size component.
-- interrupts: interrupt specifier (refer to the interrupt binding)
-
-Typically an MDIO bus might have several children.
-
-Example:
-	mdio@107009c {
-		#address-cells = <1>;
-		#size-cells = <0>;
-		compatible = "mscc,ocelot-miim";
-		reg = <0x107009c 0x36>, <0x10700f0 0x8>;
-		interrupts = <14>;
-
-		phy0: ethernet-phy@0 {
-			reg = <0>;
-		};
-	};