drm/amd/powerplay: error out on forcing clock setting not supported

drm/amd/powerplay: error out on forcing clock setting not supported

For Arcturus, forcing clock to some specific level is not supported
with 54.18 and onwards SMU firmware. As according to firmware team,
they adopt new gfx dpm tuned parameters which can cover all the use
case in a much smooth way. Thus setting through driver interface
is not needed and maybe do a disservice.

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>