drm/i915/overlay: Make the overlay control struct opaque.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c
index 3533355..0a7d3e6 100644
--- a/drivers/gpu/drm/i915/intel_overlay.c
+++ b/drivers/gpu/drm/i915/intel_overlay.c
@@ -170,6 +170,29 @@
     u16 RESERVEDG[0x100 / 2 - N_HORIZ_UV_TAPS * N_PHASES];
 };
 
+struct intel_overlay {
+	struct drm_device *dev;
+	struct intel_crtc *crtc;
+	struct drm_i915_gem_object *vid_bo;
+	struct drm_i915_gem_object *old_vid_bo;
+	int active;
+	int pfit_active;
+	u32 pfit_vscale_ratio; /* shifted-point number, (1<<12) == 1.0 */
+	u32 color_key;
+	u32 brightness, contrast, saturation;
+	u32 old_xscale, old_yscale;
+	/* register access */
+	u32 flip_addr;
+	struct drm_i915_gem_object *reg_bo;
+	/* flip handling */
+	uint32_t last_flip_req;
+	int hw_wedged;
+#define HW_WEDGED		1
+#define NEEDS_WAIT_FOR_FLIP	2
+#define RELEASE_OLD_VID		3
+#define SWITCH_OFF		4
+};
+
 static struct overlay_registers *
 intel_overlay_map_regs_atomic(struct intel_overlay *overlay,
 			      int slot)