According to MS when Windows 10 first came out, All AMD GCN GPU Cards should be able to run DX12 but not all of it features.

This 5 year old Tech articles explains about DX12 and shows which AMD GPUs can run DX12 or some of it features: Exclusive: The Nvidia and AMD DirectX 12 Editorial - Complete DX12 Graphic Card List with Specificat... 

Here is an partial list from 5 years ago showing which AMD GPUs support DX12.0: Exclusive: The Nvidia and AMD DirectX 12 Editorial - Complete DX12 Graphic Card List with Specificat...  

But that is all I know about the subject.

Did find this old thread at AMD Forums concerning 7670M GPU card where kingfish answered correctly: Direct x12