media: staging/media/bcm2048: remove driver

This driver has seen no substantial effort to move it out of
staging for 6 years. And after asking around nobody stepped up
to do the remaining work. So remove it.

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