sched/fair: improve fairness efficiency

Measured using hackbench:

PRE-patch :      4.542422684 seconds time elapsed   ( +-  47.40% )
POST-page :      2.389409991 seconds time elapsed   ( +-  47.40% )

Which shows a significant improvement of ~47.40%

**Original Patch showed significant graphical slowness on wakeup**
Lets raise the granularity period and see if that fixes the issues we were seeing with initial patch. 

Signed-off-by: Paul Reioux <reioux@gmail.com>
Signed-off-by: Lens-F <tnoah12@gmail.com>