UPSTREAM: tracing: Prepare to add preempt and irq trace events

UPSTREAM: tracing: Prepare to add preempt and irq trace events

commit aaecaa0b5f31794f1711247da4b5883a6ff98163 upstream.

In preparation of adding irqsoff and preemptsoff enable and disable trace
events, move required functions and code to make it easier to add these events
in a later patch. This patch is just code movement and no functional change.
Link: http://lkml.kernel.org/r/20171006005432.14244-2-joelaf@google.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kernel-team@android.com
Signed-off-by: Joel Fernandes <joelaf@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>