audio: update properties to fix namespace violations

Update properties to add vendor.audio prefix where missing
and remove unused ones to fix namespace violations.

Change-Id: I3723ae3e366178e87eff81001a0f1fd133cc4404
diff --git a/hal/msm8974/platform.c b/hal/msm8974/platform.c
index fd9d06b..d0e429a 100644
--- a/hal/msm8974/platform.c
+++ b/hal/msm8974/platform.c
@@ -3056,7 +3056,7 @@
 
     be_dai_name_table = NULL;
 
-    property_get("persist.audio.dualmic.config",value,"");
+    property_get("persist.vendor.audio.dualmic.config",value,"");
     if (!strcmp("endfire", value)) {
         dual_mic_config = true;
     }