arm64: topology: add MPIDR-based detection

Create cpu topology based on MPIDR. When hardware sets MPIDR to sane
values, this method will always work. Therefore it should also work well
as the fallback method. [1]

When we have multiple processing elements in the system, we create
the cpu topology by mapping each affinity level (from lowest to highest)
to threads (if they exist), cores, and clusters.

We combine data from all higher affinity levels into cluster_id
so we don't lose any information from MPIDR. [2]

[1] http://www.spinics.net/lists/arm-kernel/msg317445.html
[2] https://lkml.org/lkml/2014/4/23/703



[Raise the priority of the error message if we don't discover topology
now that we can read it from MPIDIR -- broonie]

Change-Id: I1e9dfd752f4ca0cb2309073439748dcbd0efa3be
Signed-off-by: Zi Shen Lim <zlim@broadcom.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Patch-mainline: linux-arm-kernel 5/2/2014, 20:38
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>