Enable Gelu fp32/bf16 in CPU path using Mkldnn implementation (#58525)
Summary:
Enable Gelu bf16/fp32 in CPU path using Mkldnn implementation. User doesn't need to_mkldnn() explicitly. New Gelu fp32 performs better than original one.
Add Gelu backward for https://github.com/pytorch/pytorch/pull/53615.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58525
Reviewed By: ejguan
Differential Revision: D29940369
Pulled By: ezyang
fbshipit-source-id: df9598262ec50e5d7f6e96490562aa1b116948bf
