ARM: 7011/1: Add ARM cpu topology definition

The affinity between ARM processors is defined in the MPIDR register.
We can identify which processors are in the same cluster,
and which ones have performance interdependency. We can define the
cpu topology of ARM platform, that is then used by sched_mc and sched_smt.

The default state of sched_mc and sched_smt config is disable.
When enabled, the behavior of the scheduler can be modified with
sched_mc_power_savings and sched_smt_power_savings sysfs interfaces.

Changes since v4 :
*  Remove unnecessary parentheses and blank lines

Changes since v3 :
* Update the format of printk message
* Remove blank line

Changes since v2 :
* Update the commit message and some comments

Changes since v1 :
* Update the commit message
* Add read_cpuid_mpidr in arch/arm/include/asm/cputype.h
* Modify header of arch/arm/kernel/topology.c
* Modify tests and manipulation of MPIDR's bitfields
* Modify the place and dependancy of the config
* Modify Noop functions

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
sched: Ensure cpu_power periodic update

With a lot of small task, the softirq sched is nearly never called
when no_hz is enable. Te load_balance is mainly called with
the newly_idle mode which doesn't update the cpu_power.
Add a next_update field which ensure a maximum update period when
there is short activity

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
ARM: cpu topology: Enable ARCH_POWER

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
ARM: topology: save cpu id of each core
ARM: topology: Update topology according to current sched_mc mode

Conflicts:

	arch/arm/kernel/topology.c