inductor: make fallback for cpu scatter_add (#108220)
For inductor cpu backend, the scatter_add will use ```atomic_add```, which get a worse performance, currently, we make fallback for it to avoid performance regression compared with eager mode(single socket of SKX):
```
basic_gnn_gin 1.16x(after) Vs 0.509x(before)
basic_gnn_sage 1.064x(after) Vs 0.496x (before)
basic_gnn_gcn 1.373x(aftre) Vs 0.720x(before)
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/108220
Approved by: https://github.com/jgong5, https://github.com/desertfire
