media: Revert "media: vimc: propagate pixel format in the stream"

This reverts commit b6c61a6c.

The requested pixelformat is being propagated from the capture to the
tpg in the sensor.

This was a bad design choice, as we start having the following issues:

* We set a pixelformat in the capture;
* We set matching media bus formats in the subdevices pads;
* Link validate looks fine (sizes matches, media bus formats matches);
* Issue: if some of the subdevice doesn't know how to generate the
requested pixelformat in the capture, then stream_on fails. This is bad
because capture says it supports that pixelformat, everything looks
fine, but it is not, and there is no way to find it out through the
links.

This patch was implemented so we could request any pixelformat from the
pipeline regardeless of the media bus format configured between pads.
Not all pixelformat can be mapped into a media bus code (e.g.
multiplanar formats), so with this patch we could request those
pixelformats from the tpg.

Solution: map pixelformats to media bus codes as before, and implement
conversions to other pixelformats in the capture to support multiplanar.

So first step to this solution is to revert this patch.

Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Lucas A. M. Magalhaes <lucmaga@gmail.com>
Tested-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>