ANDROID: sched: fair: balance for single core cluster

Android will unset SD_LOAD_BALANCE for single core cluster domain and
for some product it is true to have a single core cluster and the MC
domain thus lacks the SD_LOAD_BALANCE flag. This will cause
select_task_rq_fair logic break and the task will spin forever
in that core.

Fixes: 00bbe7d6 "ANDROID: sched: EAS & 'single cpu per cluster'/cpu hotplug interoperability"

Bug: 141334320
Test: boot and see task on core7 scheduled correctly
Change-Id: I7c2845b1f7bc1d4051eb3ad6a5f9838fb0b1ba04
Signed-off-by: Wei Wang <wvw@google.com>
Signed-off-by: minaripenguin <minaripenguin@users.noreply.github.com>