hal: add DSDA support on APQ targets

-This change adds DSDA support for APQ based targets
 where external modem is used for voice calls.
-Add new CSD API to support local call hold.

Change-Id: I7743a1df43dc1abac4e325ff104ec1bb64c9e12b
diff --git a/hal/msm8916/platform.h b/hal/msm8916/platform.h
index f12697c..4ab5394 100644
--- a/hal/msm8916/platform.h
+++ b/hal/msm8916/platform.h
@@ -19,6 +19,7 @@
 
 #ifndef QCOM_AUDIO_PLATFORM_H
 #define QCOM_AUDIO_PLATFORM_H
+#include <sound/voice_params.h>
 
 enum {
     FLUENCE_NONE,
@@ -205,6 +206,7 @@
 typedef int (*stop_voice_t)(uint32_t);
 typedef int (*start_playback_t)(uint32_t);
 typedef int (*stop_playback_t)(uint32_t);
+typedef int (*set_lch_t)(uint32_t, enum voice_lch_mode);
 typedef int (*start_record_t)(uint32_t, int);
 typedef int (*stop_record_t)(uint32_t);
 /* CSD Client structure */
@@ -222,6 +224,7 @@
     stop_voice_t stop_voice;
     start_playback_t start_playback;
     stop_playback_t stop_playback;
+    set_lch_t set_lch;
     start_record_t start_record;
     stop_record_t stop_record;
 };