dt-bindings: timer: Convert ezchip,nps400-timer to DT schema

Convert the EZChip NPS400 Timer bindings to DT schema format. It's a
straight-forward conversion. The 2 bindings only differ in compatible
and one required property, so the schemas can be combined.

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/ezchip,nps400-timer.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/ezchip,nps400-timer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: EZChip NPS400 Timers
+
+maintainers:
+  - Noam Camus <[e-mail]>
+
+properties:
+  compatible:
+    enum:
+      - ezchip,nps400-timer0
+      - ezchip,nps400-timer1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+required:
+  - compatible
+  - clocks
+
+additionalProperties: false
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: ezchip,nps400-timer0
+    then:
+      required: [ interrupts ]
+
+examples:
+  - |
+    timer {
+        compatible = "ezchip,nps400-timer0";
+        interrupts = <3>;
+        clocks = <&sysclk>;
+    };

Documentation/devicetree/bindings/timer/ezchip,nps400-timer0.txt

···
-NPS Network Processor
-
-Required properties:
-
-- compatible :	should be "ezchip,nps400-timer0"
-
-Clocks required for compatible = "ezchip,nps400-timer0":
-- interrupts : The interrupt of the first timer
-- clocks : Must contain a single entry describing the clock input
-
-Example:
-
-timer {
-	compatible = "ezchip,nps400-timer0";
-	interrupts = <3>;
-	clocks = <&sysclk>;
-};

Documentation/devicetree/bindings/timer/ezchip,nps400-timer1.txt

···
-NPS Network Processor
-
-Required properties:
-
-- compatible :	should be "ezchip,nps400-timer1"
-
-Clocks required for compatible = "ezchip,nps400-timer1":
-- clocks : Must contain a single entry describing the clock input
-
-Example:
-
-timer {
-	compatible = "ezchip,nps400-timer1";
-	clocks = <&sysclk>;
-};