[quant] Add a new fused MovingAvg Obs + FakeQuant operator (GPU) (#61589)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/61589
Custom GPU implementation that does the observer + calculate qparams calculation on GPU.
It calls the aten fake_quant_per_tensor/channel functions to perform the fake quant step.
Test Plan:
python test/test_quantization.py TestFusedObsFakeQuant
Imported from OSS
Reviewed By: vkuzo
Differential Revision: D29682761
fbshipit-source-id: 373a50f88481b7e5b4d9e65d84a6c174bb277dd4
