Hi and welcome to the forum
Install SLED 12 SP2, current kernel is 4.4.59?

It's not just the kernel but also the X stack.... SP3 which is still in testing has 4.4.75 and the later xf86-video-amdgpu driver, but imagine the proprietary one should work since SLED 12 Sp2 is supported by AMD pro driver....

You can install the 4.12 kernel by adding the OBS kernel:stable repo, but not officially supported...

http://download.opensuse.org/reposit...able/standard/