drm/atomic: pass old crtc state to atomic_begin/flush.

In intel it's useful to keep track of some state changes with old
crtc state vs new state, for example to disable initial planes or
when a modeset's prevented during fastboot.

Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
[danvet: squash in fixup for exynos provided by Maarten.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/sti/sti_drm_crtc.c

@@ -164,7 +164,8 @@ sti_drm_crtc_mode_set_nofb(struct drm_crtc *crtc)
 	sti_drm_crtc_mode_set(crtc, &crtc->state->adjusted_mode);
 }
 
-static void sti_drm_atomic_begin(struct drm_crtc *crtc)
+static void sti_drm_atomic_begin(struct drm_crtc *crtc,
+				 struct drm_crtc_state *old_crtc_state)
 {
 	struct sti_mixer *mixer = to_sti_mixer(crtc);
 
@@ -178,7 +179,8 @@ static void sti_drm_atomic_begin(struct drm_crtc *crtc)
 	}
 }
 
-static void sti_drm_atomic_flush(struct drm_crtc *crtc)
+static void sti_drm_atomic_flush(struct drm_crtc *crtc,
+				 struct drm_crtc_state *old_crtc_state)
 {
 }