cpufreq.c/h: rework boost logic

- not cpu bound anymore
- global flag should be enough

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

- simpler and a bit more performant

Signed-off-by: SkipXS <sskkiipp@gmail.com>
dyn_hotplug.c: adapt new boost changes

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