ACPI: Separate invocations of _GTS and _BFS from _PTS and _WAK

The execution of ACPI global control methods _GTS and _BFS is
currently tied to the preparation to enter a sleep state and to the
leaving of the sleep state, respectively.  However, these functions
are called before disabling the nonboot CPUs and after enabling
them, respectively (in fact, on ACPI 1.0x systems the first of them
ought to be called before suspending devices), while according to the
ACPI specification, _GTS is to be executed right prior to entering
the system sleep state and _BFS is to be executed right after the
platfor firmware has returned control to the OS on wake up.

Move the execution of _GTS and _BFS to the right places.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Len Brown <len.brown@intel.com>