[media] doc-rst: fix the Z16 format definition

Changeset 811c6d6a4243 ("[media] V4L: fix the Z16 format definition")
fixed the definition for DocBook, but we need to replicate it
also to ReST.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
1 file changed