Revert "Fix error: implicit declaration of function 'get_cpu_idle_time_us'"

This reverts commit d8c38ad7de1de8b354cfe2384fc9f22cbaced953.

Revert "sched/accounting: Change cpustat fields to an array"

This reverts commit 774b0884ef3062b7fdbf07f82b8e46210198b65f.
Upgrade to BFQv7r6 released 19-Oct-2014
IMPROVEMENT: Introduced a new mechanism that helps get the job done
more quickly with services and applications that create or reactivate
many parallel I/O-bound processes. This is the case, for example, with
systemd at boot, or with commands like git grep.
CODE IMPROVEMENTS: Small code cleanups and improvements
.
Change-Id: I96b0553b8443af930884c292d048ccfeb13b51e2
Signed-off-by: demetris <ierokipides.dem@gmail.com>