drm/dsi: Support device shutdown

Hook up the MIPI DSI bus's .shutdown() function to allow drivers to
implement code that should be run when a device is shut down.

Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index 7209df1..944f33f 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -135,11 +135,13 @@
  * @driver: device driver model driver
  * @probe: callback for device binding
  * @remove: callback for device unbinding
+ * @shutdown: called at shutdown time to quiesce the device
  */
 struct mipi_dsi_driver {
 	struct device_driver driver;
 	int(*probe)(struct mipi_dsi_device *dsi);
 	int(*remove)(struct mipi_dsi_device *dsi);
+	void (*shutdown)(struct mipi_dsi_device *dsi);
 };
 
 #define to_mipi_dsi_driver(d) container_of(d, struct mipi_dsi_driver, driver)