- Catch up with rev 1.157 of sys/dev/acpica/acpi.c in FreeBSD:

- Catch up with rev 1.157 of sys/dev/acpica/acpi.c in FreeBSD:
    Don't forget to pass shutdown events down to children first now that we
    handle them at the bus level too.
  This should prevent acpi_cpu_idle() from doing something nasty
  in the middle of shutdown procedure(by turning of cpu_cx_count).

- Move prototype for cpu_idle_hook into <machine/md_var.h>.

- In acpi_cpu_shutdown(), use lwkt_cpusync_simple() to synchronize
  CPUs instead of dropping into DDB.

Reported-by: Rumko <rumcic at gmail.com>