media: imx.rst: Update doc to reflect fixes to interlaced capture

Also add an example pipeline for unconverted capture with interweave
on SabreAuto.

Cleanup some language in various places in the process.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>