sched: add affinity, task load information to sched tracepoints

Knowing the affinity mask and CPU usage of a task is helpful
in understanding the behavior of the system. Affinity information
has been added to the enq_deq trace event, and the migration
tracepoint now reports the load of the task migrated.

Change-Id: I29d8a610292b4dfeeb8fe16174e9d4dc196649b7
Signed-off-by: Steve Muckle <smuckle@codeaurora.org>
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>