sched/uclamp: Cater for uclamp in find_energy_efficient_cpu()'s early exit condition

If the utilization of the woken up task is 0, we skip the energy
calculation because it has no impact.

But if the task is boosted (uclamp_min != 0) will have an impact on task
placement and frequency selection. Only skip if the util is truly
0 after applying uclamp values.

Change uclamp_task_cpu() signature to avoid unnecessary additional calls
to uclamp_eff_get(). feec() is the only user now.

Fixes: 732cd75b ("sched/fair: Select an energy-efficient CPU on task wake-up")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>