ASoC: nau8325: Modify driver code and dtschema.

Merge series from Seven Lee <wtli@nuvoton.com>:

Add a driver for the Nuvoton NAU88325.

Documentation/devicetree/bindings/sound/nuvoton,nau8325.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/nuvoton,nau8325.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NAU8325 audio Amplifier
+
+maintainers:
+  - Seven Lee <WTLI@nuvoton.com>
+
+allOf:
+  - $ref: dai-common.yaml#
+
+properties:
+  compatible:
+    const: nuvoton,nau8325
+
+  reg:
+    maxItems: 1
+
+  nuvoton,vref-impedance-ohms:
+    description:
+      The vref impedance to be used in ohms. Middle of voltage enables
+      Tie-Off selection options. Due to the high impedance of the VREF
+      pin, it is important to use a low-leakage capacitor.
+
+    enum: [0, 25000, 125000, 2500]
+
+  nuvoton,dac-vref-microvolt:
+    description:
+      The DAC vref to be used in voltage. DAC reference voltage setting. Can
+      be used for minor tuning of the output level. Since the VDDA is range
+      between 1.62 to 1.98 voltage, the typical value for design is 1.8V. After
+      the minor tuning, the final microvolt are as the below.
+
+    enum: [1800000, 2700000, 2880000, 3060000]
+
+  nuvoton,alc-enable:
+    description:
+      Enable digital automatic level control (ALC) function.
+    type: boolean
+
+  nuvoton,clock-detection-disable:
+    description:
+      When clock detection is enabled, it will detect whether MCLK
+      and FS are within the range. MCLK range is from 2.048MHz to 24.576MHz.
+      FS range is from 8kHz to 96kHz. And also needs to detect the ratio
+      MCLK_SRC/LRCK of 256, 400 or 500, and needs to detect the BCLK
+      to make sure data is present. There needs to be at least 8 BCLK
+      cycles per Frame Sync.
+    type: boolean
+
+  nuvoton,clock-det-data:
+    description:
+      Request clock detection to require 2048 non-zero samples before enabling
+      the audio paths. If set then non-zero samples is required, otherwise it
+      doesn't matter.
+    type: boolean
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        codec@21 {
+            compatible = "nuvoton,nau8325";
+            reg = <0x21>;
+            nuvoton,vref-impedance-ohms = <125000>;
+            nuvoton,dac-vref-microvolt = <2880000>;
+            nuvoton,alc-enable;
+            nuvoton,clock-det-data;
+        };
+    };