Blender 2.8 add-on RadeonProRenderBlender_2.0.1 installed successfully. Add-on active. Blender "System" reports "no compatible GPUs" under OPENCL tab.
I have tried this with both "Standard Distribution" from Blender and compiled Blender (latest version Feb 23 2019).
I have also installed Blender 2.79 with 1.85 add-on and it is detected cleanly.