x86, xen, power: fix up config dependencies on PM

Xen save/restore needs bits of code enabled by PM_SLEEP, and PM_SLEEP
depends on PM.  So make XEN_SAVE_RESTORE depend on PM and PM_SLEEP
depend on XEN_SAVE_RESTORE.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/xen/Kconfig

@@ -23,3 +23,8 @@ config XEN_MAX_DOMAIN_MEMORY
          according to the maximum possible memory size of a Xen
          domain.  This array uses 1 page per gigabyte, so there's no
          need to be too stingy here.
+
+config XEN_SAVE_RESTORE
+       bool
+       depends on PM
+       default y

kernel/power/Kconfig

@@ -82,7 +82,7 @@ config PM_SLEEP_SMP
 
 config PM_SLEEP
 	bool
-	depends on SUSPEND || HIBERNATION
+	depends on SUSPEND || HIBERNATION || XEN_SAVE_RESTORE
 	default y
 
 config SUSPEND