Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Improve style(9) in the previous commit.

Call AcpiLeaveSleepStatePrep() in interrupt disabled context
(described in ACPICA source code).

- Move intr_disable() and intr_restore() from acpi_wakeup.c to acpi.c
and call AcpiLeaveSleepStatePrep() in interrupt disabled context.
- Add acpi_wakeup_machdep() to execute wakeup MD procedures and call
it twice in interrupt disabled/enabled context (ia64 version is
just dummy).
- Rename wakeup_cpus variable in acpi_sleep_machdep() to suspcpus in
order to be shared by acpi_sleep_machdep() and acpi_wakeup_machdep().
- Move identity mapping related code to acpi_install_wakeup_handler()
(i386 version) for preparation of x86/acpica/acpi_wakeup.c
(MFC candidate).

Reviewed by: jkim@
MFC after: 2 days

Import ACPICA 20090521.

Canonize the include of acpi.h.

Minor style cleanups.

Add low-level ACPI support code and make a start on parsing the ACPI
interrupt information.