drm/amd/powerplay: expose supported clock domains only through sysfs

Do not expose those unsupported clock domains through sysfs on
Arcturus.

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Kevin Wang <kevin1.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>