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>