[media] v4l: vsp1: Fix struct vsp1_drm documentation

The struct vsp1_drm references a member 'planes' which doesn't exist.
Correctly identify this documentation against the 'inputs'

Signed-off-by: Kieran Bingham <[e-mail]>
Reviewed-by: Laurent Pinchart <[e-mail]>
Signed-off-by: Laurent Pinchart <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/platform/vsp1/vsp1_drm.h

···
  * vsp1_drm - State for the API exposed to the DRM driver
  * @pipe: the VSP1 pipeline used for display
  * @num_inputs: number of active pipeline inputs at the beginning of an update
- * @planes: source crop rectangle, destination compose rectangle and z-order
+ * @inputs: source crop rectangle, destination compose rectangle and z-order
  *	position for every input
  */
 struct vsp1_drm {