fx quant: types for fusion_patterns.py (#49606)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/49606
Adds more types, for readability.
Test Plan:
```
mypy torch/quantization
```
Imported from OSS
Reviewed By: jerryzh168
Differential Revision: D25643894
fbshipit-source-id: 4aad52fe4e59ad74b6e0e3acd0f98fba91561a29
