You can uninstall amdgpu-pro-clinfo (if possible). The conflicting file is clinfo utility, which is not the core of the driver.
You can try to block RX 480 in the fglrx driver (as described in my thread) and let AMDGPU-PRO claim it. I am not quite sure if it works because I don't have the hardware to test it, but it is definitely worth trying.
Just to inform you Alex. You've been whitelisted, so, now onwards you'll be able to post anywhere in DevGurus.