Remove unused libnativehelper include

Bug: 152482542
Test: build clean-up
Change-Id: Icfa84d55578c84670f6b9aa289a28d38556594e0
diff --git a/Makefile b/Makefile
index fdb11ac..6b4aa54 100644
--- a/Makefile
+++ b/Makefile
@@ -31,7 +31,6 @@
 GTEST=$(BASE)/external/googletest/googletest
 
 INCLUDES=$(foreach dir,$(SUBS),-I $(BASE)/$(dir)/include) \
-	-I $(BASE)/libnativehelper/include/nativehelper \
 	-I $(GTEST)/include -isystem $(GTEST) -Iinclude -I$(BASE)/../boringssl/include
 
 ifdef FORCE_32_BIT