dt-bindings: serial: qca,ar9330-uart: Convert to json-schema

Convert the Qualcomm Atheros AR9330 High-Speed UART
Device Tree binding documentation to json-schema.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/serial/qca,ar9330-uart.txt

-* Qualcomm Atheros AR9330 High-Speed UART
-
-Required properties:
-
-- compatible: Must be "qca,ar9330-uart"
-
-- reg: Specifies the physical base address of the controller and
-  the length of the memory mapped region.
-
-- interrupts: Specifies the interrupt source of the parent interrupt
-  controller. The format of the interrupt specifier depends on the
-  parent interrupt controller.
-
-Additional requirements:
-
-  Each UART port must have an alias correctly numbered in "aliases"
-  node.
-
-Example:
-
-	aliases {
-		serial0 = &uart0;
-	};
-
-	uart0: uart@18020000 {
-		compatible = "qca,ar9330-uart";
-		reg = <0x18020000 0x14>;
-
-		interrupt-parent = <&intc>;
-		interrupts = <3>;
-	};

Documentation/devicetree/bindings/serial/qca,ar9330-uart.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/serial/qca,ar9330-uart.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Atheros AR9330 High-Speed UART
+
+maintainers:
+  - Oleksij Rempel <o.rempel@pengutronix.de>
+
+allOf:
+  - $ref: /schemas/serial.yaml#
+
+properties:
+  compatible:
+    const: qca,ar9330-uart
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    const: uart
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+
+additionalProperties: false
+
+examples:
+  - |
+    serial@18020000 {
+      compatible = "qca,ar9330-uart";
+      reg = <0x18020000 0x14>;
+      clocks = <&ref>;
+      clock-names = "uart";
+      interrupt-parent = <&intc>;
+      interrupts = <3>;
+    };
+...