sched: extend sched_task_load tracepoint to indicate sync wakeup

Sync wakeups provide a hint to the scheduler about upcoming task
activity. Knowing which wakeups are sync wakeups from logs will
assist in workload analysis.

Change-Id: I6ffe73f2337e56b8234d4097069d5d70ab045eda
Signed-off-by: Steve Muckle <smuckle@codeaurora.org>