drm/amd/powerplay: error out when force clock level under auto dpm mode V2

Forcing clock level is supported under manual dpm mode only. Error out
when trying to set under manual mode. Instead of doing nothing and
reporting success.

V2: update for mclk/pcie clock level settings also

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>