ANDROID: cpufreq: interactive: Use idle-end notifiers

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

[AmitP: Cherry-picked this patch from
        https://git.kernel.org/cgit/linux/kernel/git/vireshk/pm.git/log/?h=cpufreq/interactive-idle-notifier

]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>