hal: Add support for AEC and NS audio effects

- Add sound devices needed to enable/disable AEC and NS
  audio effects on voice communication and voice recognition
  usecases.

Change-Id: I53ef3fc84e9ad43852cb22786731594f3e598390
diff --git a/hal/audio_hw.h b/hal/audio_hw.h
index 68e40ce..d682366 100644
--- a/hal/audio_hw.h
+++ b/hal/audio_hw.h
@@ -167,6 +167,7 @@
     audio_channel_mask_t channel_mask;
     audio_usecase_t usecase;
     bool enable_aec;
+    bool enable_ns;
 
     struct audio_device *dev;
 };