media: stkwebcam: remove deprecated driver

The stkwebcam driver does not use the vb2 framework for streaming
video, instead it implements this in the driver. This is error prone,
and nobody stepped in to convert this driver to that framework.

The hardware is very old, so the decision was made to remove it
altogether.

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