drm/i915: split page flip queueing into per-chipset functions

This makes things a little clearer and prevents us from running old code
on a new chipset that may not be supported.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewied-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index f63ee16..eddabf6 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -211,6 +211,9 @@
 	void (*fdi_link_train)(struct drm_crtc *crtc);
 	void (*init_clock_gating)(struct drm_device *dev);
 	void (*init_pch_clock_gating)(struct drm_device *dev);
+	int (*queue_flip)(struct drm_device *dev, struct drm_crtc *crtc,
+			  struct drm_framebuffer *fb,
+			  struct drm_i915_gem_object *obj);
 	/* clock updates for mode set */
 	/* cursor updates */
 	/* render clock increase/decrease */