dt-bindings: timer: Convert altr,timer-1.0 to DT schema

Convert the Altera Timer binding to DT schema format. It's a
straight-forward conversion.

Signed-off-by: Rob Herring (Arm) <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Daniel Lezcano <[e-mail]>

Documentation/devicetree/bindings/timer/altr,timer-1.0.txt

···
-Altera Timer
-
-Required properties:
-
-- compatible : should be "altr,timer-1.0"
-- reg : Specifies base physical address and size of the registers.
-- interrupts : Should contain the timer interrupt number
-- clock-frequency : The frequency of the clock that drives the counter, in Hz.
-
-Example:
-
-timer {
-	compatible = "altr,timer-1.0";
-	reg = <0x00400000 0x00000020>;
-	interrupt-parent = <&cpu>;
-	interrupts = <11>;
-	clock-frequency = <125000000>;
-};

Documentation/devicetree/bindings/timer/altr,timer-1.0.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/altr,timer-1.0.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Altera Timer
+
+maintainers:
+  - Dinh Nguyen <[e-mail]>
+
+properties:
+  compatible:
+    const: altr,timer-1.0
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clock-frequency:
+    description: Frequency of the clock that drives the counter, in Hz.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    timer@400000 {
+        compatible = "altr,timer-1.0";
+        reg = <0x00400000 0x00000020>;
+        interrupts = <11>;
+        clock-frequency = <125000000>;
+    };