To avoid users accessing them before the module has finished
initializing them and make sure they are only created if
dpm has properly initialized.
Reviewed-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NJammy Zhou <Jammy.Zhou@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>