cpufreq: zzmoove 0.5beta

Add display frequency control (switch to 40Hz when load is low)
cpufreq: zzmoove 0.5beta, reviewed by Yank555.lu

Display frequency control (switch to 40Hz when load is low) :

- add up delay
- add core based threshold (switchable)
cpufreq: zzmoove 0.5beta, reviewed by Yank555.lu

Display frequency control (switch to 40Hz when load is low) :

- add up delay
- add core based threshold (switchable)

NB: Forgot copy/pasting one code block.
cpufreq: zzmoove 0.5beta, reviewed by Yank555.lu

No need to continue to decrement delay counters once they have reached 0.