sched_tp: Add capacity_curr to cpu_capacity trace event

Whereas capacity_orig is the CPU capacity scaled by CPU architecture,
capacity_curr (current capacity) is the CPU capacity scaled by CPU
architecture and current_frequency/max_frequency.

capacity_curr is used to create the PELT clock information for
enqueue/dequeue (sched_switch) out of (not aligned) PELT sched events
in LISA's PELT simulation.
Here, the ftrace time between an enqueue/dequeue and a PELT sched event
has to be rescaled by the time-scaling factor which itself consists of
CPU capacity and current_frequency/max_frequency scaling factor. And
this is done by using a series of capacity_curr values.