[vulkan] speed_becnhmark_torch add vulkan arg to use Vulkan backend (#39076)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/39076
`--vulkan` argument to use torch benchmark on Vulkan Backend
if it is True - inputs will be converted to Vulkan backend before module.forward
Usage for mobilenetv2 fp32:
```
/build/bin/speed_benchmark_torch --model=mn-fp32.pt --input_type=float --input_dims=1,3,224,224 --warmup=1 --iter=5 --vulkan=true
```
Test Plan: Imported from OSS
Differential Revision: D21962428
Pulled By: IvanKobzarev
fbshipit-source-id: 3136af5386b6bce9ea53ba4a9019af2d312544b3
