drm/panfrost: Kill in-flight jobs on FD close

If the process who submitted these jobs decided to close the FD before
the jobs are done it probably means it doesn't care about the result.

v5:
* Add a panfrost_exception_is_fault() helper and the
  DRM_PANFROST_EXCEPTION_MAX_NON_FAULT value

v4:
* Don't disable/restore irqs when taking the job_lock (not needed since
  this lock is never taken from an interrupt context)

v3:
* Set fence error to ECANCELED when a TERMINATED exception is received

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210630062751.2832545-15-boris.brezillon@collabora.com