kernel - Add AHCI workaround for Intel mobo / Intel SSD probing bug

kernel - Add AHCI workaround for Intel mobo / Intel SSD probing bug

* On cold boot Intel SSDs for some reason seem to fail to initialize on
  the first attempt.  The AHCI port winds up getting stuck in BSY mode.
  Adjusting timeouts fails to solve the problem.  Ignoring the BSY state
  does solve the problem but is undesireable.

* Retry the initialization sequence once if a stuck BSY is detected
  as a workaround.  This appears to properly detect the SSD on the second
  attempt.

* Add a delay after clearing the power control state before starting the
  COMINIT sequence.  This solves no known issues but is probably a good
  idea.