kernel: cgroup: protect cgroup linked lists

Protecting cgroup lists to fix corruption due to race since
freeing of css_set now in new worker thread, free_css_set_work()

CRs-fixed: 715355
Change-Id: Iec4d7be0c372a17487f96bcdc1542afaff79dd1b
Signed-off-by: Srinivasarao P <spathi@codeaurora.org>
smp: Implement kick_all_cpus_sync()

Will replace the misnomed cpu_idle_wait() function which is copied a
gazillion times all over arch/*

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120507175652.049316594@linutronix.de
Apply arch: arm: lib: optimize memcpy for cortex-A15 to memutils
hells_defconfig: hC-b5.7