drm/i915: Disable the cursor for DPMS_OFF

The comments have long desired that we should switch off the cursor
along with the display plane, make it so.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 1075d43..a44b8cb 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -154,7 +154,7 @@
 	uint32_t cursor_addr;
 	int16_t cursor_x, cursor_y;
 	int16_t cursor_width, cursor_height;
-	bool cursor_visble;
+	bool cursor_visble, cursor_on;
 };
 
 #define to_intel_crtc(x) container_of(x, struct intel_crtc, base)