post_proc: include audio_effects.h from kernel exported headers

Currently, audio_effects.h header file is included with reference
to the absolute path. Instead, reference it from the kernel
exported headers.

Change-Id: I83880e0947e8b6a334b11c952fe8182b49ef5090
diff --git a/post_proc/Android.mk b/post_proc/Android.mk
index b6966e6..2cb910c 100644
--- a/post_proc/Android.mk
+++ b/post_proc/Android.mk
@@ -25,7 +25,7 @@
 
 LOCAL_C_INCLUDES := \
 	external/tinyalsa/include \
-	kernel/include/sound \
+        $(TARGET_OUT_INTERMEDIATES)/KERNEL_OBJ/usr/include \
 	$(call include-path-for, audio-effects)
 
 include $(BUILD_SHARED_LIBRARY)