arm: topology: Define TC2 sched energy and provide it to scheduler

!!! This patch is only here to be able to test provisioning of sched
energy related data from an arch topology shim layer to the scheduler.
Since there is no code today which deals with extracting sched energy
related data from the dtb or acpi, and process it in the topology shim
layer, the struct sched_energy and the related struct capacity_state
arrays are hard-coded here !!!

This patch defines the struct sched_energy and the related struct
capacity_state array for the cluster (relates to sg's in DIE sd level)
and for the core (relates to sg's in MC sd level) for a Cortex A7 as
well as for a Cortex A15. It further provides related implementations of
the sched_domain_energy_f functions (cpu_cluster_energy() and
cpu_core_energy()).

To be able to propagate this information from the topology shim layer to
the scheduler, the elements of the arm_topology[] table have been
provisioned with the appropriate sched_domain_energy_f functions.

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>