media: cedrus: Add watchdog for job completion

Currently, if job is not completed for whatever reason, userspace
application can hang on ioctl and thus become unkillable.

In order to prevent that, implement watchdog, which will complete job
after 2 seconds with error state.

Concept is borrowed from hantro driver.

Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>