media: fsl-viu: remove deprecated driver

The fsl-viu driver does not use the vb2 framework for streaming
video, instead it uses the old vb1 framework and nobody stepped in to
convert this driver to vb2.

The hardware is very old, so the decision was made to remove it
altogether since we want to get rid of the old vb1 framework.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>