add two functions to cuda tensor header file
add two functions to cuda tensor header file

nudles/incubator-singa,nudles/incubator-singa,nudles/incubator-singa,nudles/incubator-singa,nudles/incubator-singa,apache/incubator-singa,apache/incubator-singa,apache/incubator-singa,apache/incubator-singa,apache/incubator-singa