dt-bindings: nintendo-otp: Document the Wii and Wii U OTP support

Both of these consoles use the exact same two registers, even at the
same address, but the Wii U has eight banks of 128 bytes memory while
the Wii only has one, hence the two compatible strings.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20210810153036.1494-2-srinivas.kandagatla@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/nvmem/nintendo-otp.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/nvmem/nintendo-otp.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Nintendo Wii and Wii U OTP Device Tree Bindings
+
+description: |
+  This binding represents the OTP memory as found on a Nintendo Wii or Wii U,
+  which contains common and per-console keys, signatures and related data
+  required to access peripherals.
+
+  See https://wiiubrew.org/wiki/Hardware/OTP
+
+maintainers:
+  - Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
+
+allOf:
+  - $ref: "nvmem.yaml#"
+
+properties:
+  compatible:
+    enum:
+      - nintendo,hollywood-otp
+      - nintendo,latte-otp
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    otp@d8001ec {
+        compatible = "nintendo,latte-otp";
+        reg = <0x0d8001ec 0x8>;
+    };
+
+...