ASoC: msm: Add low latency playback and capture support

ADSP has support for low latency playback and capture.
Enhance msm alsa drivers for B-family to make use of
low latency mode.

Change-Id: Ie35c4697a5d6e3af12ef6681180b551c080ad182
Signed-off-by: Phani Kumar Uppalapati <phanik@codeaurora.org>
diff --git a/Documentation/devicetree/bindings/sound/qcom-audio-dev.txt b/Documentation/devicetree/bindings/sound/qcom-audio-dev.txt
index 232ddec..fed8cb4 100644
--- a/Documentation/devicetree/bindings/sound/qcom-audio-dev.txt
+++ b/Documentation/devicetree/bindings/sound/qcom-audio-dev.txt
@@ -6,6 +6,21 @@
 
  - compatible : "qcom,msm-pcm-dsp"
 
+ - qcom,msm-pcm-dsp-id : device node id
+
+* msm-pcm-low-latency
+
+Required properties:
+
+ - compatible : "qcom,msm-pcm-dsp"
+
+ - qcom,msm-pcm-dsp-id : device node id
+
+   Optional properties
+
+      - qcom,msm-pcm-low-latency : Flag indicating whether
+        the device node is of type low latency.
+
 * msm-pcm-routing
 
 Required properties:
@@ -212,7 +227,14 @@
 Example:
 
         qcom,msm-pcm {
-                compatible = "qcom,msm-pcm-dsp";
+		compatible = "qcom,msm-pcm-dsp";
+		qcom,msm-pcm-dsp-id = <0>;
+	};
+
+	qcom,msm-pcm-low-latency {
+		compatible = "qcom,msm-pcm-dsp";
+		qcom,msm-pcm-dsp-id = <1>;
+		qcom,msm-pcm-low-latency;
         };
 
         qcom,msm-pcm-routing {