sched: Skip load update for idle task

Load statistics for idle tasks is not useful in any manner. Skip load
update for such idle tasks.

CRs-Fixed: 665706
Change-Id: If3a908bad7fbb42dcb3d0a1d073a3750cf32fcf9
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
Signed-off-by: Stefanescu Cristian <howerkraft@gmail.com>
sched: Remove redundant update_runtime notifier

migration_call() will do all the things that update_runtime() does.
So let's remove it.

Furthermore, there is potential risk that the current code will catch
BUG_ON at line 689 of rt.c when do cpu hotplug while there are realtime
threads running because of enabling runtime twice while the rt_runtime
may already changed.

Change-Id: If2d953316d93c6b7e32f94bd49f2c10e64de6ed8
Signed-off-by: Neil Zhang <zhangwm@marvell.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1365685499-26515-1-git-send-email-zhangwm@marvell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Git-commit: c5405a495e88d93cf9b4f4cc91507c7f4afcb901
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[mattw@codeaurora.org: resolved trivial header file context conflict]
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>

Signed-off-by: Stefanescu Cristian <howerkraft@gmail.com>

Conflicts:
	kernel/sched/rt.c
sched: Calculate max_possible_freq based on current policy->max

Signed-off-by: Stefanescu Cristian <howerkraft@gmail.com>