drm/irq: Add drm_crtc_send_vblank_event()

This function is the KMS native variant of drm_send_vblank_event(). It
takes a struct drm_crtc * instead of a struct drm_device * and an index
of the CRTC.

Eventually the goal is to access vblank data through the CRTC only so
that the per-CRTC data can be moved to struct drm_crtc.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 8ba35c6..b78601b 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -905,6 +905,8 @@
 				     struct timeval *vblanktime);
 extern void drm_send_vblank_event(struct drm_device *dev, int crtc,
 				     struct drm_pending_vblank_event *e);
+extern void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
+				       struct drm_pending_vblank_event *e);
 extern bool drm_handle_vblank(struct drm_device *dev, int crtc);
 extern int drm_vblank_get(struct drm_device *dev, int crtc);
 extern void drm_vblank_put(struct drm_device *dev, int crtc);