drm/amd/pp: Fix bug voltage can't be OD separately on VI

Make sure to update the MCLK and SCLK flags when setting the VDDC
flags due to dependencies.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>