coresight: add event to abort tracing late on kernel panic

We call coresight_abort() early in panic pathway to avoid trace buffer
getting cluttered with uninteresting messages; however sometimes it tends
to loose important info such as kernel sending notification to all
peripheral subsystems since it happens after aborting of CoreSight trace.
Add trace event to abort tracing late in kernel panic.
trace_event_kernel_panic and trace_event_kernel_panic_late are mutually
exclusive and can be control using module parameter. With this change user
will be able to choose whether to abort CoreSight trace early or late on
kernel panic.

Change-Id: I84cc299823d929fdf8129c9c728282b32391b7c1
Signed-off-by: Sarang Joshi <spjoshi@codeaurora.org>