[quant][graphmode][fx][fp16] Add fp16 support for tanh (#52864)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/52864
Test Plan:
python test/test_quantization.py TestQuantizeFxOps.test_fixed_qprams_ops_fp16
Imported from OSS
Reviewed By: vkuzo
Differential Revision: D26672271
fbshipit-source-id: 539017c3045a28fc95f4f9d32591c2b2d10af6c0
