[quant][graphmode][fx] Support fp16 dynamic quantization for linear (#44582)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/44582
Test Plan:
test_quantize_fx.py
Imported from OSS
Reviewed By: vkuzo
Differential Revision: D23665974
fbshipit-source-id: 19ba6c61a9c77ef570b00614016506e9a2729f7c
