Before running any opencl program, please check the "clinfo" command's output. If "clinfo" does not list this gpu, then opencl program may fail as well.
The reason might be due some installation issue. So, please ensure that you've installed a compatible driver for this gpu. Searching for a compatible driver points here: https://support.amd.com/en-us/download/embedded?os=Windows%207%20-%2032
Did you install this driver?