This patch updates EHCI suspend/resume so that its essential
components work on a few different implementations:

   - make root hub suspend/resume work
   - make remote wakeup work (given CONFIG_USB_SUSPEND patch)
   - separate root hub suspend/resume from PCI suspend/resume
   - say if controller supports remote wakeup (on this system)
   - sysfs register dump unavailable if controller is suspended

Plus a handful of minor cleanups.  Please merge, along with the
"hcd-0506.patch" I sent last week.

Tested by modifying sysfs power/state files, since ACPI doesn't
work on this system (so I can't test system suspend/resume):

  - For root hub(*) ... suspend/resume works, also remote wakeup
  - PCI controller ... suspend/resume works, remote wakeup
    signals PME# (according to "lspci -vv"), but that's ignored
    on my test sytem

Regardless of whether USB was active, "echo 1 > /proc/acpi/sleep"
produced a system that wouldn't resume, and the same result
came from "echo standby > /sys/power/state".  So that's about
as far as I can take this testing for now.

- Dave

(*) Doing this relies on the CONFIG_USB_SUSPEND patch.  Otherwise
     no USB devices respond to sysfs power/state updates.  The
     PCI suspend/resume is a superset of this.