ACPI / Wakeup: Simplify enabling of wakeup devices

To simplify the enabling of wakeup devices during system suspend and
hibernation, merge acpi_enable_wakeup_device_prep() with
acpi_disable_wakeup_device() and remove unnecessary (and no longer
valid) comments from the latter.  Rename acpi_enable_wakeup_device()
to acpi_enable_wakeup_devices() and acpi_disable_wakeup_device()
to acpi_disable_wakeup_devices(), because these functions usually
operate on multiple device objects.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/sleep.h b/drivers/acpi/sleep.h
index 25b8bd1..d882180 100644
--- a/drivers/acpi/sleep.h
+++ b/drivers/acpi/sleep.h
@@ -2,9 +2,8 @@
 extern u8 sleep_states[];
 extern int acpi_suspend(u32 state);
 
-extern void acpi_enable_wakeup_device_prep(u8 sleep_state);
-extern void acpi_enable_wakeup_device(u8 sleep_state);
-extern void acpi_disable_wakeup_device(u8 sleep_state);
+extern void acpi_enable_wakeup_devices(u8 sleep_state);
+extern void acpi_disable_wakeup_devices(u8 sleep_state);
 
 extern struct list_head acpi_wakeup_device_list;
 extern struct mutex acpi_device_lock;