Removes bionic's dependence on stlport

Only affects tests/benchmarks. Confirmed passing on arm.

Change-Id: If158e23e8cd06e7597ef6f3c9376f6799b467e62
diff --git a/tests/Android.build.mk b/tests/Android.build.mk
index c1a0f16..4019a29 100644
--- a/tests/Android.build.mk
+++ b/tests/Android.build.mk
@@ -77,7 +77,7 @@
     $($(module)_ldlibs_$(build_type)) \
 
 ifeq ($(build_type),target)
-  include external/stlport/libstlport.mk
+  include external/libcxx/libcxx.mk
 
   include $(BUILD_$(build_target))
 endif