Moved all DNN test cases into benchmark dir

hpvm/benchmarks/dnn_benchmarks/.gitignore

hpvm/benchmarks/dnn_benchmarks/hpvm-c/CMakeLists.txt

...s/hpvm-c/benchmarks/alexnet2_cifar10/alexnet2_cifar10.cpp

...-c/benchmarks/alexnet2_cifar10/alexnet2_cifar10_cudnn.cpp

...vm-c/benchmarks/alexnet2_cifar10/data/quant_ranges_rt.txt

...s/hpvm-c/benchmarks/alexnet2_cifar10/data/tuner_confs.txt

...rks/hpvm-c/benchmarks/alexnet_cifar10/alexnet_cifar10.cpp

...vm-c/benchmarks/alexnet_cifar10/alexnet_cifar10_cudnn.cpp

...pvm-c/benchmarks/alexnet_cifar10/data/quant_ranges_rt.txt

...ks/hpvm-c/benchmarks/alexnet_cifar10/data/tuner_confs.txt

...s/hpvm-c/benchmarks/alexnet_imagenet/alexnet_imagenet.cpp

...-c/benchmarks/alexnet_imagenet/alexnet_imagenet_cudnn.cpp

...vm-c/benchmarks/alexnet_imagenet/data/quant_ranges_rt.txt

...s/hpvm-c/benchmarks/alexnet_imagenet/data/tuner_confs.txt

...ks/hpvm-c/benchmarks/lenet_mnist/data/quant_ranges_rt.txt

...hmarks/hpvm-c/benchmarks/lenet_mnist/data/tuner_confs.txt

..._benchmarks/hpvm-c/benchmarks/lenet_mnist/lenet_mnist.cpp

...marks/hpvm-c/benchmarks/lenet_mnist/lenet_mnist_cudnn.cpp

...m-c/benchmarks/mobilenet_cifar10/data/quant_ranges_rt.txt

.../hpvm-c/benchmarks/mobilenet_cifar10/data/tuner_confs.txt