Created by: jczaja

Growing number of activations of DNNL made part of code bloated and perhaps not very efficient Goal is to refactor it , so new activations are easier to add/maintain. Relevant code:

https://github.com/PaddlePaddle/Paddle/blob/eec10aaba2f6c19bf08f3e4983a1dabcca4a5844/paddle/fluid/platform/mkldnn_reuse.h#L977-L988