ACPI: Hibernate erroneously disabled Suspend wakeup devices

S4 suspend to disk will disable GPE's permanently
because acpi_gpe_sleep_prepare() does not have
a counterpart at resume time.  Thus, those devices
became unavailable for wakeup from subsequent
S3 suspend-to-ram.

Here acpi_gpe_sleep_prepare() is removed, and upon suspend
acpi_enable_wakeup_device() gets its functionality.
Upon resume, acpi_disable_wakeup_device() restores the state.

https://bugzilla.novell.com/show_bug.cgi?id=292300

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Len Brown <len.brown@intel.com>