drm/amd/display: Do not put drm_atomic_state on resume

drm_atomic_helper_resume now puts it for us. See relevant patch here:
https://lists.freedesktop.org/archives/dri-devel/2017-October/154268.html



Signed-off-by: Leo (Sunpeng) Li <sunpeng.li@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>