dt-bindings: serial: Convert lantiq,asc to DT schema

Convert the Lantiq SoC ASC UART binding to DT schema. There are no such
clock identifier defines nor a user with clocks, so drop the example
with clocks.

Signed-off-by: "Rob Herring (Arm)" <[e-mail]>
Reviewed-by: Thierry Reding <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/devicetree/bindings/serial/lantiq,asc.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/serial/lantiq,asc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Lantiq SoC ASC serial controller
+
+maintainers:
+  - John Crispin <[e-mail]>
+  - Songjun Wu <[e-mail]>
+
+allOf:
+  - $ref: /schemas/serial/serial.yaml#
+
+properties:
+  compatible:
+    const: lantiq,asc
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    items:
+      - description: TX interrupt
+      - description: RX interrupt
+      - description: Error interrupt
+
+  clocks:
+    items:
+      - description: Frequency clock
+      - description: Gate clock
+
+  clock-names:
+    items:
+      - const: freq
+      - const: asc
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/mips-gic.h>
+
+    serial@16600000 {
+        compatible = "lantiq,asc";
+        reg = <0x16600000 0x100000>;
+        interrupts = <GIC_SHARED 103 IRQ_TYPE_LEVEL_HIGH>,
+                     <GIC_SHARED 105 IRQ_TYPE_LEVEL_HIGH>,
+                     <GIC_SHARED 106 IRQ_TYPE_LEVEL_HIGH>;
+    };

Documentation/devicetree/bindings/serial/lantiq_asc.txt

···
-Lantiq SoC ASC serial controller
-
-Required properties:
-- compatible : Should be "lantiq,asc"
-- reg : Address and length of the register set for the device
-- interrupts: the 3 (tx rx err) interrupt numbers. The interrupt specifier
-  depends on the interrupt-parent interrupt controller.
-
-Optional properties:
-- clocks: Should contain frequency clock and gate clock
-- clock-names: Should be "freq" and "asc"
-
-Example:
-
-asc0: serial@16600000 {
-	compatible = "lantiq,asc";
-	reg = <0x16600000 0x100000>;
-	interrupt-parent = <&gic>;
-	interrupts = <GIC_SHARED 103 IRQ_TYPE_LEVEL_HIGH>,
-		<GIC_SHARED 105 IRQ_TYPE_LEVEL_HIGH>,
-		<GIC_SHARED 106 IRQ_TYPE_LEVEL_HIGH>;
-	clocks = <&cgu CLK_SSX4>, <&cgu GCLK_UART>;
-	clock-names = "freq", "asc";
-};
-
-asc1: serial@e100c00 {
-	compatible = "lantiq,asc";
-	reg = <0xE100C00 0x400>;
-	interrupt-parent = <&icu0>;
-	interrupts = <112 113 114>;
-};