cpufreq_ondemand.c: remove ignore_nice_load

Signed-off-by: SkipXS <sskkiipp@gmail.com>
cpufreq_ondemand.c: remove powersave_bias

Signed-off-by: SkipXS <sskkiipp@gmail.com>
cpufreq_ondemand.c : simplify boost

- mod_timer is a more efficient way to update the expire field of an
active timer (if the timer is inactive it will be activated) see:
(https://www.kernel.org/doc/htmldocs/device-drivers/API-mod-timer.html)

Signed-off-by: SkipXS <sskkiipp@gmail.com>