unified: Ensure delays do not time out prematurely

Ensures that all APIs which accept a timeout value wait for at least
the specified amount of time, and do not time out prematurely.

* The kernel now waits for the next system clock tick to occur before
  the timeout interval is considered to have started. (That is, the only
  way to ensure a delay of N tick intervals is to wait for N+1 ticks
  to occur.)

* Gets rid of ticks -> milliseconds -> ticks conversion in task_sleep()
  and fiber_sleep() legacy APIs, since this introduces rounding that
  -- coupled with the previous change -- can alter the number of ticks
  being requested during the sleep operation.

* Corrects work queue API that was incorrectly shown to use a delay
  measured in ticks, rather than milliseconds.

Change-Id: I8b04467237b24fb0364c8f344d872457418c18da
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
7 files changed