sched/core: Add trace point for cpu isolation

Add tracepoint to capture the cpu isolation event including KPI for
time it took to isolate.

Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>
[markivx: forward port to 4.14, conflict in trace events file]
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>

Change-Id: I51bc0c0f59e5ed42b19fca25e6013efb9e24cfd2
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>