media: vicodec: Drop unused job_abort()

The vicodec does not use the aborting field. In fact, this driver
can't really cancel any work, since it performs all the work
in device_run().

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>