dt-bindings: rtc: Convert Amlogic Meson vrtc controller binding

Convert Amlogic Meson vrtc controller binding to yaml.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/d820d54b-d082-589a-621f-2795d885696a@gmail.comSigned-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Documentation/devicetree/bindings/rtc/amlogic,meson-vrtc.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/amlogic,meson-vrtc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Amlogic Virtual RTC (VRTC)
+
+maintainers:
+  - Neil Armstrong <neil.armstrong@linaro.org>
+
+description: |
+  This is a Linux interface to an RTC managed by firmware, hence it's
+  virtual from a Linux perspective.  The interface is 1 register where
+  an alarm time (in seconds) is to be written.
+  The alarm register is a simple scratch register shared between the
+  application processors (AP) and the secure co-processor (SCP.)  When
+  the AP suspends, the SCP will use the value of this register to
+  program an always-on timer before going sleep. When the timer expires,
+  the SCP will wake up and will then wake the AP.
+
+allOf:
+  - $ref: rtc.yaml#
+
+properties:
+  compatible:
+    enum:
+      - amlogic,meson-vrtc
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    rtc@a8 {
+      compatible = "amlogic,meson-vrtc";
+      reg = <0x000a8 0x4>;
+    };

Documentation/devicetree/bindings/rtc/rtc-meson-vrtc.txt

-* Amlogic Virtual RTC (VRTC)
-
-This is a Linux interface to an RTC managed by firmware, hence it's
-virtual from a Linux perspective.  The interface is 1 register where
-an alarm time (in seconds) is to be written.
-
-Required properties:
-- compatible: should be "amlogic,meson-vrtc"
-- reg: physical address for the alarm register
-
-The alarm register is a simple scratch register shared between the
-application processors (AP) and the secure co-processor (SCP.)  When
-the AP suspends, the SCP will use the value of this register to
-program an always-on timer before going sleep. When the timer expires,
-the SCP will wake up and will then wake the AP.
-
-Example:
-
-	vrtc: rtc@0a8 {
-		compatible = "amlogic,meson-vrtc";
-		reg = <0x0 0x000a8 0x0 0x4>;
-	};