dt-bindings: clock: imx8mp: Add audiomix block control

Unlike the other block control IPs in i.MX8M, the audiomix is mostly a
series of clock gates and muxes. Add DT bindings for this IP.
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Tested-by: Adam Ford <aford173@gmail.com> #imx8mp-beacon-kit
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Tested-by: Richard Leitner <richard.leitner@skidata.com>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://lore.kernel.org/r/20230301163257.49005-3-marex@denx.de

Documentation/devicetree/bindings/clock/imx8mp-audiomix.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/imx8mp-audiomix.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP i.MX8MP AudioMIX Block Control Binding
+
+maintainers:
+  - Marek Vasut <marex@denx.de>
+
+description: |
+  NXP i.MX8M Plus AudioMIX is dedicated clock muxing and gating IP
+  used to control Audio related clock on the SoC.
+
+properties:
+  compatible:
+    const: fsl,imx8mp-audio-blk-ctrl
+
+  reg:
+    maxItems: 1
+
+  power-domains:
+    maxItems: 1
+
+  clocks:
+    minItems: 7
+    maxItems: 7
+
+  clock-names:
+    items:
+      - const: ahb
+      - const: sai1
+      - const: sai2
+      - const: sai3
+      - const: sai5
+      - const: sai6
+      - const: sai7
+
+  '#clock-cells':
+    const: 1
+    description:
+      The clock consumer should specify the desired clock by having the clock
+      ID in its "clocks" phandle cell. See include/dt-bindings/clock/imx8mp-clock.h
+      for the full list of i.MX8MP IMX8MP_CLK_AUDIOMIX_ clock IDs.
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - power-domains
+  - '#clock-cells'
+
+additionalProperties: false
+
+examples:
+  # Clock Control Module node:
+  - |
+    #include <dt-bindings/clock/imx8mp-clock.h>
+
+    clock-controller@30e20000 {
+        compatible = "fsl,imx8mp-audio-blk-ctrl";
+        reg = <0x30e20000 0x10000>;
+        #clock-cells = <1>;
+        clocks = <&clk IMX8MP_CLK_AUDIO_ROOT>,
+                 <&clk IMX8MP_CLK_SAI1>,
+                 <&clk IMX8MP_CLK_SAI2>,
+                 <&clk IMX8MP_CLK_SAI3>,
+                 <&clk IMX8MP_CLK_SAI5>,
+                 <&clk IMX8MP_CLK_SAI6>,
+                 <&clk IMX8MP_CLK_SAI7>;
+        clock-names = "ahb",
+                      "sai1", "sai2", "sai3",
+                      "sai5", "sai6", "sai7";
+        power-domains = <&pgc_audio>;
+    };
+
+...