drm/atomic: use helper to get crtc state

DRM core provide helper to access crtc state.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1458045960-25193-1-git-send-email-a.hajda@samsung.com
1 file changed