hal: Add dynamic enablement of AEC/NS for VoIP

Add capability to dynamically enable or disable AEC/NS audio effects
on DSP for a VoIP call.

Change-Id: I9cb2b6cf95d936d770eda47bd87db02534f302b4
diff --git a/hal/Android.mk b/hal/Android.mk
index d2ef726..cbf766a 100644
--- a/hal/Android.mk
+++ b/hal/Android.mk
@@ -368,6 +368,10 @@
     LOCAL_SRC_FILES += audio_extn/ip_hdlr_intf.c
 endif
 
+ifeq ($(strip $($AUDIO_FEATURE_ENABLED_DYNAMIC_ECNS)),true)
+    LOCAL_CFLAGS += -DDYNAMIC_ECNS_ENABLED
+endif
+
 LOCAL_CFLAGS += -Wall -Werror
 
 LOCAL_COPY_HEADERS_TO   := mm-audio