drm/dsi: Add routine to unregister a DSI device

A driver calling mipi_dsi_device_register_full() might want to remove
the device once it's done. It might also require it in an error handling
path in case something went wrong.

Create mipi_dsi_device_unregister() for this purpose and use it within
mipi_dsi_remove_device_fn() as it does the same thing.

Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
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 a914116..06e0a93 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -210,6 +210,7 @@
 struct mipi_dsi_device *
 mipi_dsi_device_register_full(struct mipi_dsi_host *host,
 			      const struct mipi_dsi_device_info *info);
+void mipi_dsi_device_unregister(struct mipi_dsi_device *dsi);
 struct mipi_dsi_device *of_find_mipi_dsi_device_by_node(struct device_node *np);
 int mipi_dsi_attach(struct mipi_dsi_device *dsi);
 int mipi_dsi_detach(struct mipi_dsi_device *dsi);