drm/amdgpu: add GMC support for Stoney
drm/amdgpu: add GMC support for Stoney

Stoney is GMC 8.x.

Signed-off-by: Samuel Li <a7eae956e4a8c15296b8c1249a63b6fee09cb1a3@amd.com>
Signed-off-by: Alex Deucher <08dc22c6156113f2deff178e35e3ed9b24d6af9e@amd.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs