cpufreq: interactive_pro: Replace load evaluation with scheduler hints

Scheduler has more information about what potential load could be
on each CPU in the future. Use scheduler hints instead of busy/idle
time from past window.

In addition, replace mod_timer_pinned() with del_timer(), add_timer_on().
mod_timer_pinned() always adds timer onto current CPU. Interactive
governor expects each CPU's timers to be running on the same CPU, but
load change callback might be triggered from other CPUs.

Replacing mod_timer_pinned() with del_timer() and add_timer_on()
guarantees timers are still run on the right CPU even if another CPU
reschedules the timer.

Change-Id: Ic7c917bffe7bfef60c9ef93072276aa873927ad7
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>