drm/xe: Don't restart parallel queues multiple times on GT reset

drm/xe: Don't restart parallel queues multiple times on GT reset

In case of parallel submissions multiple GuC id will point to the
same exec queue and on GT reset such exec queues will get restarted
multiple times which is not desirable.

v2: don't use exec_queue_enabled() which could race,
    do the same for xe_guc_submit_stop (Matt B)

Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2295
Cc: Jonathan Cavitt <[email protected]>
Cc: Himal Prasad Ghimiray <[email protected]>
Cc: Matthew Auld <[email protected]>
Cc: Matthew Brost <[email protected]>
Cc: Tejas Upadhyay <[email protected]>
Reviewed-by: Matthew Brost <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Nirmoy Das <[email protected]>