drm/amd/pp: Remove uncessary extra vcn pg cntl in smu

the vcn power will be controlled by VCN.

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>