Fix for verify_dynamo on ROCm (#97013)
Prior to this change ROCm was not exiting check_cuda, causing an exception at packaging.version.parse(torch.version.cuda), this change exits check_cuda if torch.version.cuda is None
```
python verify_dynamo.py
Python version: 3.9.16
`torch` version: 2.1.0a0+git2b2f10c
CUDA version: None
ROCM version: 5.4
All required checks passed
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/97013
Approved by: https://github.com/jithunnair-amd, https://github.com/malfet, https://github.com/kit1980
