hal: add ip-handler audio extension module

Add ip-handler interface audio extension module to
handle MS12 security mechanism.

Change-Id: I599325a5d0d7ae47eced243bead7ed2a4e25ebb0
diff --git a/hal/Android.mk b/hal/Android.mk
index 908619d..5059932 100644
--- a/hal/Android.mk
+++ b/hal/Android.mk
@@ -358,6 +358,11 @@
     LOCAL_SHARED_LIBRARIES += libaudio_log_utils
 endif
 
+ifeq ($(strip $($AUDIO_FEATURE_IP_HDLR_ENABLED)),true)
+    LOCAL_CFLAGS += -DAUDIO_EXTN_IP_HDLR_ENABLED
+    LOCAL_SRC_FILES += audio_extn/ip_hdlr_intf.c
+endif
+
 LOCAL_CFLAGS += -Wall -Werror
 
 LOCAL_COPY_HEADERS_TO   := mm-audio