drm/amdgpu: Enable CGCG/LS for GC 9.4.3

Enable coarse grain clockgating/light sleep for GC v9.4.3. Remove
programming that is not meant for GC 9.4.3.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>