[quant][graphmode][fx] Add support for elu (#43375)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/43375
Porting op tests from test_quantize_jit.py
Test Plan:
TestQuantizeFxOps
Imported from OSS
Reviewed By: z-a-f
Differential Revision: D23257043
fbshipit-source-id: 22360610d87ef98d25871daff3fdc3dbb3ec5bdb
