ANDROID: sched/fair: add arch scaling function for max frequency capping

To be able to scale the cpu capacity by this factor introduce a call to
the new arch scaling function arch_scale_max_freq_capacity() in
update_cpu_capacity() and provide a default implementation which returns
SCHED_CAPACITY_SCALE.

Another subsystem (e.g. cpufreq) or architectural or platform specific
code can overwrite this default implementation, exactly as for frequency
and cpu invariance. It has to be enabled by the arch by defining
arch_scale_max_freq_capacity to the actual implementation.

Change-Id: I770a8b1f4f7340e9e314f71c64a765bf880f4b4d
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Git-commit: 44791a47
Git-repo: https://android.googlesource.com/kernel/common/


Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>