Fix mixed precision issue in TF DistilBert (#6915)
Fix mixed precision issue in TF DistilBert (#6915)

* Remove hard-coded uses of float32 to fix mixed precision use in TF Distilbert

* fix style

* fix gelu dtype issue in TF Distilbert

* fix numeric overflow while using half precision
huggingface/transformers,huggingface/transformers,huggingface/transformers,huggingface/transformers,huggingface/pytorch-transformers