drm/i915: Use plane state for primary plane updates.

Pass in the atomic states to allow for proper updates.
This removes uses of intel_crtc->config and direct access
to plane->state.

This breaks the last bit of kgdboc, but that appears to be dead code.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452164052-21752-7-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

drivers/gpu/drm/i915/i915_drv.h

@@ -652,9 +652,6 @@ struct drm_i915_display_funcs {
 			  struct drm_i915_gem_object *obj,
 			  struct drm_i915_gem_request *req,
 			  uint32_t flags);
-	void (*update_primary_plane)(struct drm_crtc *crtc,
-				     struct drm_framebuffer *fb,
-				     int x, int y);
 	void (*hpd_irq_setup)(struct drm_device *dev);
 	/* clock updates for mode set */
 	/* cursor updates */