audio: Add support to enable split A2DP

- Add new audio extension module for a2dp
- Add support to configure AFE encoder based
  on BT device capabilities
- Add support for soft handoff to re-configure
  AFE based on new BT device capability

Change-Id: I5d710fda1a8d8fa3b5d85aaa2b3096cff8fd7ce5
diff --git a/hal/msm8916/platform.h b/hal/msm8916/platform.h
index 756c749..cd5aeb7 100644
--- a/hal/msm8916/platform.h
+++ b/hal/msm8916/platform.h
@@ -98,6 +98,8 @@
     SND_DEVICE_OUT_SPEAKER_AND_HDMI,
     SND_DEVICE_OUT_BT_SCO,
     SND_DEVICE_OUT_BT_SCO_WB,
+    SND_DEVICE_OUT_BT_A2DP,
+    SND_DEVICE_OUT_SPEAKER_AND_BT_A2DP,
     SND_DEVICE_OUT_VOICE_TTY_FULL_HEADPHONES,
     SND_DEVICE_OUT_VOICE_TTY_VCO_HEADPHONES,
     SND_DEVICE_OUT_VOICE_TTY_HCO_HANDSET,