drm/amd/powerplay: set Arcturus default fclk as bootup value on dpm disabled

On fclk dpm disabled, the default dpm table will be setup with only one
level and clock frequency as bootup value.

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>