cpufreq: interactive: Revert timer start modification

commit f8b276565ce95bd788af0fc8d060f92632590a40
(cpufreq: Sync on thread migration optimizations)
introduced a change to cpufreq_interactive_timer_start() in order
to reschedule the timer differently based on whether min or max
is changed. A better way is to reschedule the timer only when
necessary.

Revert timer start modification in preparation for the final fix.

Change-Id: I13f3b75a6eee03ac6380c24db899806a9bfbc96a
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>
cpufreq: interactive: restructure CPUFREQ_GOV_LIMITS

The cpufreq_interactive_timer gets cancelled and rescheduled
whenever the cpufreq_policy is changed. When the cpufreq policy is
changed at a rate faster than the sampling_rate of the interactive
governor, then the governor misses to change the target frequency
for long duration. The patch removes the need of cancelling the
timers when policy->min is changed.

Change-Id: Ibd98d151e1c73b8bd969484583ff98ee9f1135ef
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Git-commit: 9b97d655a558607c5d46ef1f21365d695f8d1ee2
Git-Repo: https://android.googlesource.com/kernel/common.git
[junjiew@codeaurora.org: resolve merge conflicts]
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>
cpufreq: interactive: Simplify frequency calculations

Previously, complicated calculations led to oscillating cpu
frequencies that ruined user experience even on high-end
devices. Revert to the classic calculations based on a
percentage of current max frequency.  This way, we're using
freqs more evenly and much more predictable.

Change-Id: Id7898618607f0e26b272e3c74932a92380e3db7a