PR #13289: [XLA:CPU] [oneDNN] Fix accuracy issue with layernorm fusion
PR #13289: [XLA:CPU] [oneDNN] Fix accuracy issue with layernorm fusion

Imported from GitHub PR https://github.com/openxla/xla/pull/13289

This PR fixes the accuracy issue seen with F16 ViT model by adding a default value for epsilon. It also adds a slight variation seen for TF layernorm pattern in XLA for F32,BF16,F16.

Copybara import of the project:

--
f7adf21334c812be1052fc966339aa6308910e81 by Kanvi Khanna <kanvi.khanna@intel.com>:

Update TF layernorm pattern for f16
Add default value for epsilon which fixes accuracy
Add tests

Merging this change closes #13289

FUTURE_COPYBARA_INTEGRATE_REVIEW=https://github.com/openxla/xla/pull/13289 from Intel-tensorflow:kanvi/Fix_LN_accuracy f7adf21334c812be1052fc966339aa6308910e81
