cpufreq: interactive: Optimize sync_freq implementation

Don't let frequency drop below sync_freq if either load or
frequency among other cpus is above a certain threshold,
not necessarily both.

Change-Id: Iada28e08e812498e16d5189b309a7314f88814dd
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>

Signed-off-by: klozz <xxx.reptar.rawrr.xxx@gmail.com>
 cpufreq: interactive: Use parts of native boost routine

Not all governors are created equal. Set boostpulse_endtime
and floor_freq to smoothen the timer routine.

[franciscofranco] removed boostpulse_endtime from the
original commit because I'm not using it.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>

Signed-off-by: klozz <xxx.reptar.rawrr.xxx@gmail.com>