drm/atomic: Clean up wait_for_vblanks, v2.

Stop relying on a per crtc_state last_vblank_count, we shouldn't touch
crtc_state after commit. Move it to atomic_state->crtcs.

Also stop re-using new_crtc_state->enable, we can now simply set a
bitmask with crtc_crtc_mask.

Changes since v1:
- Keep last_vblank_count in __drm_crtc_state.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/8e4759a4-24d3-3f80-bd1a-1e7a9c83b612@linux.intel.com

include/drm/drm_atomic.h

@@ -145,6 +145,7 @@ struct __drm_crtcs_state {
 	struct drm_crtc_state *state;
 	struct drm_crtc_commit *commit;
 	s64 __user *out_fence_ptr;
+	unsigned last_vblank_count;
 };
 
 struct __drm_connnectors_state {

include/drm/drm_crtc.h

@@ -90,8 +90,6 @@ struct drm_plane_helper_funcs;
  * @plane_mask: bitmask of (1 << drm_plane_index(plane)) of attached planes
  * @connector_mask: bitmask of (1 << drm_connector_index(connector)) of attached connectors
  * @encoder_mask: bitmask of (1 << drm_encoder_index(encoder)) of attached encoders
- * @last_vblank_count: for helpers and drivers to capture the vblank of the
- * 	update to ensure framebuffer cleanup isn't done too early
  * @adjusted_mode: for use by helpers and drivers to compute adjusted mode timings
  * @mode: current mode timings
  * @mode_blob: &drm_property_blob for @mode
@@ -137,9 +135,6 @@ struct drm_crtc_state {
 	u32 connector_mask;
 	u32 encoder_mask;
 
-	/* last_vblank_count: for vblank waits before cleanup */
-	u32 last_vblank_count;
-
 	/* adjusted_mode: for use by helpers and drivers */
 	struct drm_display_mode adjusted_mode;