Add `<LuaJIT>/android/<arch>` to exported include directories.

love/src/jni/LuaJIT-2.1/Android.mk

@@ -4,6 +4,6 @@ include $(CLEAR_VARS)
 
 LOCAL_MODULE := libluajit
 LOCAL_SRC_FILES := android/$(TARGET_ARCH_ABI)/libluajit.a
-LOCAL_EXPORT_C_INCLUDES := ${LOCAL_PATH}/src
+LOCAL_EXPORT_C_INCLUDES := ${LOCAL_PATH}/src ${LOCAL_PATH}/android/$(TARGET_ARCH_ABI)
 
 include $(PREBUILT_STATIC_LIBRARY)