disable gentle fair sleeps and use ARCH_POWER

Sleeper Fairness is a concept used by CFS which treat sleeping/waiting tasks as if they were in a run queue. This implies tasks which spend most of the time waiting for an user input and such will get a fair share of CPU when they need it. Disabling Gentle Fair Sleepers could improve UI responsiveness. Arch Power patch causes arch dependent power functions to be used instead of generic high resolution timer ticks and double ticks.

Signed-off-by: Rachit Rawat <rachit.rc96@gmail.com>