dt-bindings: net: brcm,unimac-mdio: convert to the json-schema

This helps validating DTS files.

Introduced example binding changes:
1. Fixed reg formatting
2. Swapped #address-cells and #size-cells incorrect values
3. Renamed node: s/phy/ethernet-phy/

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/brcm,unimac-mdio.yaml

@@ -0,0 +1,84 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/brcm,unimac-mdio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Broadcom UniMAC MDIO bus controller
+
+maintainers:
+  - Rafał Miłecki <rafal@milecki.pl>
+
+allOf:
+  - $ref: mdio.yaml#
+
+properties:
+  compatible:
+    enum:
+      - brcm,genet-mdio-v1
+      - brcm,genet-mdio-v2
+      - brcm,genet-mdio-v3
+      - brcm,genet-mdio-v4
+      - brcm,genet-mdio-v5
+      - brcm,unimac-mdio
+
+  reg:
+    minItems: 1
+    items:
+      - description: base register
+      - description: indirect accesses to larger than 16-bits MDIO transactions
+
+  reg-names:
+    minItems: 1
+    items:
+      - const: mdio
+      - const: mdio_indir_rw
+
+  interrupts:
+    oneOf:
+      - description: >
+          Interrupt shared with the Ethernet MAC or Ethernet switch this MDIO
+          block is integrated from
+      - items:
+          - description: |
+              "mdio done" interrupt
+          - description: |
+              "mdio error" interrupt
+
+  interrupt-names:
+    oneOf:
+      - const: mdio_done_error
+      - items:
+          - const: mdio_done
+          - const: mdio_error
+
+  clocks:
+    description: A reference to the clock supplying the MDIO bus controller
+
+  clock-frequency:
+    description: >
+      The MDIO bus clock that must be output by the MDIO bus hardware, if
+      absent, the default hardware values are used
+
+unevaluatedProperties: false
+
+required:
+  - reg
+  - reg-names
+  - '#address-cells'
+  - '#size-cells'
+
+examples:
+  - |
+    mdio@403c0 {
+        compatible = "brcm,unimac-mdio";
+        reg = <0x403c0 0x8>, <0x40300 0x18>;
+        reg-names = "mdio", "mdio_indir_rw";
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        ethernet-phy@0 {
+            compatible = "ethernet-phy-ieee802.3-c22";
+            reg = <0>;
+        };
+    };