drm/amd/powerplay: honor the OD settings

Set the soft/hard max settings as max possible to
not violate the OD settings.

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