passing to Transformer blocks. Set it to `None` if normalization is not needed.
embedding_proj_norm_type (`str`, *optional*, defaults to None):
The normalization layer to apply on the input `proj_embedding`. Set it to `None` if normalization is not
needed.
encoder_hid_proj_type (`str`, *optional*, defaults to `linear`):
The projection layer to apply on the input `encoder_hidden_states`. Set it to `None` if
`encoder_hidden_states` is `None`.