dt-bindings: serial: Convert arm,mps2-uart to DT schema

Convert the Arm MPS2 UART binding to DT schema. It is a straight-forward
conversion.

Signed-off-by: "Rob Herring (Arm)" <robh@kernel.org>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20250506220012.2545470-1-robh@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: robherring

Documentation/devicetree/bindings/serial/arm,mps2-uart.txt

@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/serial/arm,mps2-uart.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Arm MPS2 UART
+
+maintainers:
+  - Vladimir Murzin <vladimir.murzin@arm.com>
+
+allOf:
+  - $ref: /schemas/serial/serial.yaml#
+
+properties:
+  compatible:
+    const: arm,mps2-uart
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    items:
+      - description: RX interrupt
+      - description: TX interrupt
+      - description: Overrun interrupt
+
+  clocks:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    serial@40004000 {
+        compatible = "arm,mps2-uart";
+        reg = <0x40004000 0x1000>;
+        interrupts = <0>, <1>, <12>;
+        clocks = <&sysclk>;
+    };