cpufreq: interactive: remove boostpulse related code
Boostpulse is supposed to decrease GUI latency (or improve GUI response)
but it is designed in the userspace and supposed to receive the pulse
signal via sysfs interface. It is not a good idea to place the latency
sensitive code outside kernel. Removal of this code will theoretically
increase the efficiency of interactive governor since there wil be fewer
sysfs variables to monitor. Get rid of this useless feature.