groupnorm: graph mode static quant support (#39095)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/39095
Hooks up groupnorm to graph mode static quant
Test Plan:
```
python test/test_quantization.py TestQuantizeScriptPTSQOps.test_group_norm
```
Imported from OSS
Differential Revision: D21885257
fbshipit-source-id: 3415c4de76181b026d2f5bfebab130fea29e1d1e
