[quant][graphmode][fx][fp16] Add fp16 support for sub (#52809)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/52809
Test Plan:
python test/test_quantization.py TestQuantizeFxOps.test_sub
Imported from OSS
Reviewed By: vkuzo
Differential Revision: D26655618
fbshipit-source-id: b47966ee1b75a2f814b9019d8d16b2da2212f5da
