drm/xe: Capture GuC CT snapshot when stopped

It is useful capture the GuC CT snapshot if the GuC CT has been
forcefully put into the stopped state. Enable snapshot capture when in
this state.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240405211632.223568-3-matthew.brost@intel.com