[quant][core][gpu][improvement] Made plan and run for quantized cudnn conv op conform with Conv_v8.cpp
Summary:
The workspace and plan in Conv_v8.cpp diverged from Conv.cpp after
https://github.com/pytorch/pytorch/pull/60755 landed. This PR conforms
the two files in regards to the workspace and plan.
Test Plan:
```
python test/test_quantization.py -k test_qconv2d_cudnn
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/76788
Approved by: https://github.com/jerryzh168
