dt-bindings: timer: Convert cirrus,clps711x-timer to DT schema

Convert the Cirrus CLPS711x timer binding to DT schema format. It's a
straight-forward conversion.

Drop the aliases node and second example which aren't relevant.

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/cirrus,clps711x-timer.txt

···
-* Cirrus Logic CLPS711X Timer Counter
-
-Required properties:
-- compatible: Shall contain "cirrus,ep7209-timer".
-- reg       : Address and length of the register set.
-- interrupts: The interrupt number of the timer.
-- clocks    : phandle of timer reference clock.
-
-Note: Each timer should have an alias correctly numbered in "aliases" node.
-
-Example:
-	aliases {
-		timer0 = &timer1;
-		timer1 = &timer2;
-	};
-
-	timer1: timer@80000300 {
-		compatible = "cirrus,ep7312-timer", "cirrus,ep7209-timer";
-		reg = <0x80000300 0x4>;
-		interrupts = <8>;
-		clocks = <&clks 5>;
-	};
-
-	timer2: timer@80000340 {
-		compatible = "cirrus,ep7312-timer", "cirrus,ep7209-timer";
-		reg = <0x80000340 0x4>;
-		interrupts = <9>;
-		clocks = <&clks 6>;
-	};

Documentation/devicetree/bindings/timer/cirrus,clps711x-timer.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/timer/cirrus,clps711x-timer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Cirrus Logic CLPS711X Timer Counter
+
+maintainers:
+  - Alexander Shiyan <[e-mail]>
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - cirrus,ep7312-timer
+          - const: cirrus,ep7209-timer
+      - const: cirrus,ep7209-timer
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    timer@80000300 {
+        compatible = "cirrus,ep7312-timer", "cirrus,ep7209-timer";
+        reg = <0x80000300 0x4>;
+        interrupts = <8>;
+        clocks = <&clks 5>;
+    };