media: v4l2-core: introduce a helper to unregister a spi subdev

Introduce a new video4linux2 spi helper, to unregister a subdev.
This allows to get rid of some more ifdefs.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
index 8e66edd..e287865 100644
--- a/include/media/v4l2-common.h
+++ b/include/media/v4l2-common.h
@@ -285,6 +285,13 @@ struct v4l2_subdev *v4l2_spi_new_subdev(struct v4l2_device *v4l2_dev,
 void v4l2_spi_subdev_init(struct v4l2_subdev *sd, struct spi_device *spi,
 		const struct v4l2_subdev_ops *ops);
 
+/**
+ * v4l2_spi_subdev_unregister - Unregister a v4l2_subdev
+ *
+ * @sd: pointer to &struct v4l2_subdev
+ */
+void v4l2_spi_subdev_unregister(struct v4l2_subdev *sd);
+
 #else
 
 static inline struct v4l2_subdev *
@@ -299,6 +306,8 @@ v4l2_spi_subdev_init(struct v4l2_subdev *sd, struct spi_device *spi,
 		     const struct v4l2_subdev_ops *ops)
 {}
 
+static inline void v4l2_spi_subdev_unregister(struct v4l2_subdev *sd)
+{}
 #endif
 
 /* ------------------------------------------------------------------------- */