dt-bindings: serial: qcom,msm-uart: Convert to DT schema

Convert the Qualcomm MSM SoC UART (non-DMA) bindings to DT schema.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20221201133036.45288-1-krzysztof.kozlowski@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/serial/qcom,msm-uart.txt

-* MSM Serial UART
-
-The MSM serial UART hardware is designed for low-speed use cases where a
-dma-engine isn't needed. From a software perspective it's mostly compatible
-with the MSM serial UARTDM except that it only supports reading and writing one
-character at a time.
-
-Required properties:
-- compatible: Should contain "qcom,msm-uart"
-- reg: Should contain UART register location and length.
-- interrupts: Should contain UART interrupt.
-- clocks: Should contain the core clock.
-- clock-names: Should be "core".
-
-Example:
-
-A uart device at 0xa9c00000 with interrupt 11.
-
-serial@a9c00000 {
-	compatible = "qcom,msm-uart";
-	reg = <0xa9c00000 0x1000>;
-	interrupts = <11>;
-	clocks = <&uart_cxc>;
-	clock-names = "core";
-};

Documentation/devicetree/bindings/serial/qcom,msm-uart.yaml

+# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/serial/qcom,msm-uart.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm MSM SoC Serial UART
+
+maintainers:
+  - Bjorn Andersson <andersson@kernel.org>
+  - Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
+
+description:
+  The MSM serial UART hardware is designed for low-speed use cases where a
+  dma-engine isn't needed. From a software perspective it's mostly compatible
+  with the MSM serial UARTDM except that it only supports reading and writing
+  one character at a time.
+
+properties:
+  compatible:
+    const: qcom,msm-uart
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    items:
+      - const: core
+
+  interrupts:
+    maxItems: 1
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - clock-names
+  - clocks
+  - interrupts
+  - reg
+
+unevaluatedProperties: false
+
+allOf:
+  - $ref: /schemas/serial/serial.yaml#
+
+examples:
+  - |
+    serial@a9c00000 {
+        compatible = "qcom,msm-uart";
+        reg = <0xa9c00000 0x1000>;
+        interrupts = <11>;
+        clocks = <&uart_cxc>;
+        clock-names = "core";
+    };