[pytorch][vulkan] realistic benchmark size for depthwise (#89948)
Update benchmark size to be bigger tensors to get mor realistic numbers
Differential Revision: [D41006643](https://our.internmc.facebook.com/intern/diff/D41006643/)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/89948
Approved by: https://github.com/digantdesai, https://github.com/salilsdesai
