since there are situation which send singal to idle thread already,
CONFIG_SCHED_CHILD_STATUS=y
CONFIG_SCHED_HAVE_PARENT=y
Signo SIGCHLD will send to parent group, when child exit
Change-Id: Iceb2ac41948c1c3418839a3b5de70985d48c75d1
Signed-off-by: ligd <liguiding1@xiaomi.com>