[fx2trt][torchbench] enable shufflenet lowering (#71562)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/71562
Previously we have some unsupported ops and the perf improvement is not promising (10% on batch size 32)
```
Unsupported node types in the model:
acc_ops.reshape: ((), {'input': torch.float16})
mean: ((torch.float16,), {})
```
After the diff stack, we don't have any unsupported nodes.
Also moved `lower_to_trt` to lower.py.
Test Plan: buck run mode/dev-nosan -c python.package_style=inplace scripts/dsy842974287/cu_model:vision
Reviewed By: wushirong
Differential Revision: D33483843
fbshipit-source-id: 4a54e25af3e5a6e4a299737994b60b999f529aa6
(cherry picked from commit add0077c27e7155fff7aaab96c506a872a00b83c)
