dbr quant: extend qconfig_dict support to functions, part 1 (#69758)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/69758
Extends DBR quant `qconfig_dict['object_type']` support to function types,
with the restriction that a parent module must have a qconfig.
A future PR will remove the restriction above (it is due to some technical
debt), to keep PR sizes small.
Test Plan:
```
python test/test_quantization.py TestQuantizeDBR
```
Reviewed By: jerryzh168
Differential Revision: D33020217
Pulled By: vkuzo
fbshipit-source-id: ce8a8185f9c87d437e1319ff6f19e8f6adf41e02
