Introduce CONFIG_SUSPEND for suspend-to-Ram and standby

Introduce CONFIG_SUSPEND representing the ability to enter system sleep
states, such as the ACPI S3 state, and allow the user to choose SUSPEND
and HIBERNATION independently of each other.

Make HOTPLUG_CPU be selected automatically if SUSPEND or HIBERNATION has
been chosen and the kernel is intended for SMP systems.

Also, introduce CONFIG_PM_SLEEP which is automatically selected if
CONFIG_SUSPEND or CONFIG_HIBERNATION is set and use it to select the
code needed for both suspend and hibernation.

The top-level power management headers and the ACPI code related to
suspend and hibernation are modified to use the new definitions (the
changes in drivers/acpi/sleep/main.c are, mostly, moving code to reduce
the number of ifdefs).

There are many other files in which CONFIG_PM can be replaced with
CONFIG_PM_SLEEP or even with CONFIG_SUSPEND, but they can be updated in
the future.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/base/power/power.h

@@ -5,7 +5,7 @@
 extern void device_shutdown(void);
 
 
-#ifdef CONFIG_PM
+#ifdef CONFIG_PM_SLEEP
 
 /*
  * main.c
@@ -62,7 +62,7 @@ extern int resume_device(struct device *);
  */
 extern int suspend_device(struct device *, pm_message_t);
 
-#else /* CONFIG_PM */
+#else /* CONFIG_PM_SLEEP */
 
 
 static inline int device_pm_add(struct device * dev)