drm/amdgpu: print mmhub client name for dimgrey_cavefish

This makes it easier to debug what block is causing the fault, same as
sienna_cichlid.

Signed-off-by: Tao Zhou <tao.zhou1@amd.com>
Reviewed-by: Jiansong Chen <Jiansong.Chen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>