lisa._assets.kmodules.sched_tp: Hide UTIL_AVG_UNCHANGED in sched_util_est_se

UTIL_AVG_UNCHANGED is an internal util_est state bit and should not be
exposed via util_est.enqueued in the sched_util_est_se trace event.

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>