dt-bindings: net: convert mdio-mux-meson-g12a.txt to dt-schema

Convert MDIO bus multiplexer/glue of Amlogic G12a SoC family bindings
to dt-schema.

Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/devicetree/bindings/net/amlogic,g12a-mdio-mux.yaml

@@ -0,0 +1,80 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/amlogic,g12a-mdio-mux.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MDIO bus multiplexer/glue of Amlogic G12a SoC family
+
+description:
+  This is a special case of a MDIO bus multiplexer. It allows to choose between
+  the internal mdio bus leading to the embedded 10/100 PHY or the external
+  MDIO bus.
+
+maintainers:
+  - Neil Armstrong <neil.armstrong@linaro.org>
+
+allOf:
+  - $ref: mdio-mux.yaml#
+
+properties:
+  compatible:
+    const: amlogic,g12a-mdio-mux
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: peripheral clock
+      - description: platform crytal
+      - description: SoC 50MHz MPLL
+
+  clock-names:
+    items:
+      - const: pclk
+      - const: clkin0
+      - const: clkin1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    mdio-multiplexer@4c000 {
+        compatible = "amlogic,g12a-mdio-mux";
+        reg = <0x4c000 0xa4>;
+        clocks = <&clkc_eth_phy>, <&xtal>, <&clkc_mpll>;
+        clock-names = "pclk", "clkin0", "clkin1";
+        mdio-parent-bus = <&mdio0>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        mdio@0 {
+            reg = <0>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+        };
+
+        mdio@1 {
+            reg = <1>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            ethernet-phy@8 {
+                compatible = "ethernet-phy-id0180.3301",
+                             "ethernet-phy-ieee802.3-c22";
+                interrupts = <GIC_SPI 9 IRQ_TYPE_LEVEL_HIGH>;
+                reg = <8>;
+                max-speed = <100>;
+            };
+        };
+    };
+...