ARM: dts: msm: Add an energy model for the SDM845 CPUs

The Energy Aware Scheduler (EAS) requires an energy model to be
present in device tree, one that includes capacity and energy
information for cpus and clusters.

Note that the scheduler treats SDM845 as having two clusters since
four of the CPUs are in a different clock domain with a different
IPC value compared to the rest.

Change-Id: I54f353f3d52bd17d9019b7f5f339a90250668a82
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>