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/rcar-du/rcar_du_crtc.c

@@ -496,7 +496,8 @@ static bool rcar_du_crtc_mode_fixup(struct drm_crtc *crtc,
 	return true;
 }
 
-static void rcar_du_crtc_atomic_begin(struct drm_crtc *crtc)
+static void rcar_du_crtc_atomic_begin(struct drm_crtc *crtc,
+				      struct drm_crtc_state *old_crtc_state)
 {
 	struct drm_pending_vblank_event *event = crtc->state->event;
 	struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
@@ -512,7 +513,8 @@ static void rcar_du_crtc_atomic_begin(struct drm_crtc *crtc)
 	}
 }
 
-static void rcar_du_crtc_atomic_flush(struct drm_crtc *crtc)
+static void rcar_du_crtc_atomic_flush(struct drm_crtc *crtc,
+				      struct drm_crtc_state *old_crtc_state)
 {
 	struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);