doc-rst: pixfmt-004: Add an extra reference

One paragraph mentions the YUV422 formats, but doesn't provide
a cross-ref. Add it.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This commit is contained in:
Mauro Carvalho Chehab 2016-07-03 17:25:37 -03:00
commit 5f4c138500