[NVIDIA TF] Add remaining GPU BF16 cwise ops
cc @reedwm  CC @cantonios 
https://github.com/tensorflow/tensorflow/issues/59743

Previously, we added support for most BF16 ops in TF except for the cwise ops which were not used by various initializers or created by grappler. This PR enables the remaining cwise ops which have CPU bf16 implementations already.

Tested `tensorflow/python/kernel_tests/math_ops/cwise_ops_test.py` and `tensorflow/python/kernel_tests/math_ops/cwise_ops_binary_test.py`