Merge changes I50a2bc22,I9a97bf27,Id187e448,I572a5cf8,I389c3ab5, ...

* changes:
  atrace: only start trace when starting trace
  Add SDE tracing to gfx category
  Add clk tracing to freq category
  Trace clock_enable and clock_disable events.
  atrace: preempt and irq disable section tracing
  Add tracing tags to vibrator