dt-bindings: power: reset: convert nvmem-reboot-mode bindings to YAML

Convert the DT binding document for nvmem-reboot-mode from .txt to YAML.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

Documentation/devicetree/bindings/power/reset/nvmem-reboot-mode.txt

-NVMEM reboot mode driver
-
-This driver gets reboot mode magic value from reboot-mode driver
-and stores it in a NVMEM cell named "reboot-mode". Then the bootloader
-can read it and take different action according to the magic
-value stored.
-
-Required properties:
-- compatible: should be "nvmem-reboot-mode".
-- nvmem-cells: A phandle to the reboot mode provided by a nvmem device.
-- nvmem-cell-names: Should be "reboot-mode".
-
-The rest of the properties should follow the generic reboot-mode description
-found in reboot-mode.txt
-
-Example:
-	reboot-mode {
-		compatible = "nvmem-reboot-mode";
-		nvmem-cells = <&reboot_mode>;
-		nvmem-cell-names = "reboot-mode";
-
-		mode-normal     = <0xAAAA5501>;
-		mode-bootloader = <0xBBBB5500>;
-		mode-recovery   = <0xCCCC5502>;
-		mode-test       = <0xDDDD5503>;
-	};

Documentation/devicetree/bindings/power/reset/nvmem-reboot-mode.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/reset/nvmem-reboot-mode.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Generic NVMEM reboot mode
+
+maintainers:
+  - Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
+
+description:
+  This driver gets the reboot mode magic value from the reboot-mode driver
+  and stores it in the NVMEM cell named "reboot-mode". The bootloader can
+  then read it and take different action according to the value.
+
+properties:
+  compatible:
+    const: nvmem-reboot-mode
+
+  nvmem-cells:
+    description:
+      A phandle pointing to the nvmem-cells node where the vendor-specific
+      magic value representing the reboot mode is stored.
+    maxItems: 1
+
+  nvmem-cell-names:
+    items:
+      - const: reboot-mode
+
+patternProperties:
+  "^mode-.+":
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: Vendor-specific mode value written to the mode register
+
+required:
+  - compatible
+  - nvmem-cells
+  - nvmem-cell-names
+
+additionalProperties: false
+
+examples:
+  - |
+    reboot-mode {
+        compatible = "nvmem-reboot-mode";
+        nvmem-cells = <&reboot_reason>;
+        nvmem-cell-names = "reboot-mode";
+        mode-recovery = <0x01>;
+        mode-bootloader = <0x02>;
+    };
+...