According to GPU-Z, AMD has all the applicable API's enabled including OpenCL for your GPU card. So it seems like the AMD driver is correctly installed.
Do you have a HD 8670/M GPU card? On GPU-Z click on the upper Right box "LOOKUP" to determine the exact GPU card you have and what version of OpenCl it is showing to support.
According to Premiere Pro Compatible OpenCl GPU cards yours isn't listed: https://helpx.adobe.com/premiere-pro/system-requirements.html#hardware-acceleration
Also according to TechPowerUp for the HD 8670M uses OpenCL version 1.2:
Does Premiere Pro support OpenCl version 1.1 and above?
AMD RX 5500/5600/5700 supports OpenCl 2.1 and above. It is possible that Premiere Pro doesn't support OpenCL 1.2 which why you can't enable it in Adobe program.
Possibly it supports only OpenCL version 2.0 or newer to work in Premiere Pro.
Adobe has a Technical Chat line at Premiere Pro website but you need to have an account with them to use that feature.
EDIT: Is this a laptop or Desktop? What is the Make & Model of Laptop, CPU and GPUs in Laptop, Motherboard and CPU if Desktop.
I believe the issue is your GPU card is not supported by Premiere Pro for OpenCL use. If you use one of the first versions of Premiere Pro and OpenCL works in your GPU card that would indicate that the new Premiere Pro versions doesn't support OpenCL version 1.2 anymore.