cpufreq: interactive: Align timer windows for all CPUs

It's more advantageous to evaluate all CPUs at same time so that
interactive governor gets a complete picture of the load on
each CPU at a specific time. It could also reduce number of speed
changes made if there are many CPUs controlled by same policy. In
addition, waking up all CPUs at same time would allow the cluster
to go into a deeper sleep state when it's idle.

Change-Id: I6915050c5339ef1af106eb906ebe4b7c618061e2
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>
cpufreq: interactive: Reset last evaluated jiffy in idle callback

When CPU has been busy for a long time, last evaluated jiffy will be
quite behind because the timer would have been canceled. We don't want
to schedule a timer to fire in the past as load will always be 100%.

Reset last evaluated jiffy so that timer will be scheduled for the
next window.

Change-Id: Ie25e65eab1f16acdeda267987ca605d653f1f32a
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>
cpufreq: interactive: Round up timer_rate to match jiffy

Timers are scheduled in unit of jiffies. Round up timer_rate so that
it matches the actual sampling period.

Change-Id: I47e666f835752528331f50b1e76784e6d67f8bcf
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>