ANDROID: implement max frequency capping

Implements the Max Frequency Capping Engine (MFCE) getter function
topology_get_max_freq_scale() to provide the scheduler with a
maximum frequency scaling correction factor for more accurate cpu
capacity handling by being able to deal with max frequency capping.

This scaling factor describes the influence of running a cpu with a
current maximum frequency (policy) lower than the maximum possible
frequency (cpuinfo).

The factor is:

  policy_max_freq(cpu) << SCHED_CAPACITY_SHIFT / cpuinfo_max_freq(cpu)

It also implements the MFCE setter function arch_set_max_freq_scale()
which is called from cpufreq_set_policy().

Change-Id: I59e52861ee260755ab0518fe1f7183a2e4e3d0fc
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Git-commit: b6a1f3e4
Git-repo: https://android.googlesource.com/kernel/common/


[satyap@codeaurora.org: trivial merge conflict resolution in
drivers/base/arch_topology.c where msm-4.14 has efficiency variable
which is not part of Android Common, so, the conflict and resolution]
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>