Interestingly, AMD is claiming that their upcoming Vega Frontier Editions chips outperform Nvidia's current P100 Deep Learning chip. http://hexus.net/media/uploaded/2017/5/30f5633b-1bbf-49b7-9f...
While AMD doesn't create something like cuDNN to go along with their cards, no real work will start being done in porting most important DL libraries to AMD cards. And even in that case, it will be a lost generation for AMD, only in the 2nd generation where AMD actually offers a real alternative in DL to NVIDIA, you will start to see some real progress being done with it.