align qconv benchmark to conv benchmark (#42761)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/42761
Makes the qconv benchmark follow the conv benchmark exactly. This way
it will be easy to compare q vs fp with the same settings.
Test Plan:
```
cd benchmarks/operator_benchmark
python -m pt.qconv_test
python -m pt.conv_test
```
Imported from OSS
Reviewed By: jerryzh168
Differential Revision: D23012533
fbshipit-source-id: af30ee585389395569a6322f5210828432963077
