media: staging/media/soc_camera: remove this driver

The soc_camera driver (and related soc_camera-dependent sensor
drivers) is obsolete and depends on BROKEN for a long time now.
Nobody is using it, so it is time to kill it off.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>