hal: add generic handset mic definitions

-Add generic handset mic to support different use-cases
 on this single device using tx app_type config.
-The change is guarded with a system property which should
 be enabled only if tx app_type support is already available
 and generic device definition is added in acdb files.

Change-Id: I3fea2e12bd99a0d229fb5753d47dba2501ea528b
diff --git a/hal/msm8974/platform.h b/hal/msm8974/platform.h
index 4fa9442..2fa22e4 100644
--- a/hal/msm8974/platform.h
+++ b/hal/msm8974/platform.h
@@ -228,6 +228,7 @@
     SND_DEVICE_IN_HANDSET_8MIC,
     SND_DEVICE_IN_EC_REF_LOOPBACK_MONO,
     SND_DEVICE_IN_EC_REF_LOOPBACK_STEREO,
+    SND_DEVICE_IN_HANDSET_GENERIC_QMIC,
     SND_DEVICE_IN_END,
 
     SND_DEVICE_MAX = SND_DEVICE_IN_END,