Updated HPVM loop sources (input data sizes)

...SC/DNN_Benchmarks/benchmarks/alexnet/src/alexnet_loop.cpp

.../DNN_Benchmarks/benchmarks/alexnet2/src/alexnet2_loop.cpp

.../DNN_Benchmarks/benchmarks/lenet_mnist/src/lenet_loop.cpp

.../DNN_Benchmarks/benchmarks/resnet18/src/resnet18_loop.cpp

...marks/benchmarks/vgg16_cifar10/src/vgg16_cifar10_loop.cpp

...rks/benchmarks/vgg16_cifar100/src/vgg16_cifar100_loop.cpp