[media] doc-rst: Add ivtv documentation

Convert ivtv documentation to rst, update the links there
and add to media/v4l-drivers book.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/media/v4l-drivers/index.rst

@@ -26,4 +26,5 @@ License".
 	cx88
 	davinci-vpbe
 	fimc
+	ivtv
 	zr364xx