This updates the ADB driver and the three low-level ADB bus adaptor
drivers used on powermacs.  The files affected are all in
drivers/macintosh; they are adb.c, macio-adb.c, via-cuda.c and
via-pmu.c.

The main changes in this patch are:

- Remove the use of global cli/sti and replace them with local cli/sti,
  spinlocks and semaphores as appropriate.
- Use DECLARE_WORK/schedule_work instead of tq_struct/schedule_task.
- Improvements to the PMU interrupt handling and sleep/wakeup code.