audio: Skip libhdmipassthru on OSS builds

Change-Id: I23e25aa8e6ae63fcb40a0a1bd3bc68565527d176
diff --git a/hal/audio_extn/Android.mk b/hal/audio_extn/Android.mk
index b667943..1d10fd5 100644
--- a/hal/audio_extn/Android.mk
+++ b/hal/audio_extn/Android.mk
@@ -524,6 +524,8 @@
 #-------------------------------------------
 #            Build HDMI PASSTHROUGH
 #-------------------------------------------
+ifneq ($(QCPATH),)
+
 include $(CLEAR_VARS)
 
 LOCAL_MODULE := libhdmipassthru
@@ -583,6 +585,8 @@
 LOCAL_HEADER_LIBRARIES += libsystem_headers
 include $(BUILD_SHARED_LIBRARY)
 
+endif
+
 #-------------------------------------------
 #            Build BATTERY_LISTENER
 #-------------------------------------------