ACPI suspend: Call _PTS before suspending devices

The ACPI 1.0 specification wants us to put devices into low power
states after executing the _PTS global control method, while ACPI
2.0 and later want us to do that in the reverse order.  The current
suspend code follows ACPI 2.0 in that respect which causes some
ACPI 1.0x systems to hang during suspend (ref.
http://bugzilla.kernel.org/show_bug.cgi?id=9528

).

Make the suspend code execute _PTS before putting devices into low
power states (ie. in accordance with ACPI 1.0x) and provide a command
line option to override the default if need be.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>