drm/amd/pp: Not call cgs interface to get display info

DC/Non DC all will update display configuration
when the display state changed
No need to get display info through cgs interface

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