ASoC: dt-bindings: add q6apm digital audio stream bindings

On AudioReach audio Framework, Audio Streams (PCM/Compressed) are managed by
Q6APM(Audio Process Manager) service. This patch adds bindings for this DAIs
exposed by the DSP.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211026111655.1702-9-srinivas.kandagatla@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/qcom,q6apm-dai.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/sound/qcom,q6apm-dai.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Qualcomm Audio Process Manager Digital Audio Interfaces binding
+
+maintainers:
+  - Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
+
+description: |
+  This binding describes the Qualcomm APM DAIs in DSP
+
+properties:
+  compatible:
+    const: qcom,q6apm-dais
+
+  reg:
+    maxItems: 1
+
+  iommus:
+    maxItems: 1
+
+required:
+  - compatible
+  - iommus
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/soc/qcom,gpr.h>
+    gpr {
+        compatible = "qcom,gpr";
+        #address-cells = <1>;
+        #size-cells = <0>;
+        qcom,domain = <GPR_DOMAIN_ID_ADSP>;
+        service@1 {
+          compatible = "qcom,q6apm";
+          reg = <1>;
+
+          #address-cells = <1>;
+          #size-cells = <0>;
+
+          apm-dai@1 {
+            compatible = "qcom,q6apm-dais";
+            iommus = <&apps_smmu 0x1801 0x0>;
+            reg = <1>;
+          };
+        };
+    };