Expand presets to `QuantizationConfig` to populate `_quantization_method` for each quantizable unit.
Expand presets to `QuantizationConfig` to populate `_quantization_method` for each quantizable unit.

FUTURE_COPYBARA_INTEGRATE_REVIEW=https://github.com/openxla/xla/pull/10626 from Intel-tensorflow:akhil/bf16_softmax d030100ea87923582aa64cdcf0fac1464051288c
