V4L/DVB: V4L2 docs: replace spaces by tabs

CC: Jonathan Corbet <corbet@lwn.net>
CC: Reviewed-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Documentation/video4linux/v4l2-framework.txt

@@ -609,4 +609,3 @@ scatter/gather method (videobuf-dma-sg), DMA with linear access
 
 Please see Documentation/video4linux/videobuf for more information on how
 to use the videobuf layer.
-