Adding layers and ops files for Imagenet DNNs

...s/soc_simulator/alexnet_imagenet/alexnet_imagenet_ops.txt

...ects/soc_simulator/alexnet_imagenet/layer_composition.txt

...projects/soc_simulator/resnet50_imagenet/construct_ops.py

...cts/soc_simulator/resnet50_imagenet/layer_composition.txt

llvm/projects/soc_simulator/resnet50_imagenet/layers.txt

...simulator/resnet50_imagenet/resnet50_imagenet_layers.txt2

...soc_simulator/resnet50_imagenet/resnet50_imagenet_ops.txt

...ojects/soc_simulator/vgg16_imagenet/layer_composition.txt

llvm/projects/soc_simulator/vgg16_imagenet/layers.txt

...jects/soc_simulator/vgg16_imagenet/vgg16_imagenet_ops.txt