Added missing file

src/Makefile.am

 
 LINKLIBS = $(PTHREAD_LIBS) $(OPT_LIBS) $(BOOST_LDFLAGS) $(BOOST_PROGRAM_OPTIONS_LIB) $(CUDA_LIBS) $(BOOST_THREAD_LIB)
 
+if BUILDCUDA
+ CUDA_SOURCES=memory/CudaMemory.cu
+else
+ CUDA_SOURCES=
+endif
+
 bin_PROGRAMS = mem
-mem_SOURCES = main.cpp memory/HeapMemory.cpp memory/CudaMemory.cu
+mem_SOURCES = main.cpp memory/HeapMemory.cpp $(CUDA_SOURCES)
 mem_CXXFLAGS = $(INCLUDES_PATH) -I/usr/local/include
 mem_CFLAGS = 
 mem_LDADD = $(LINKLIBS) -L/usr/lib64/nvidia-bumblebee/