remove software_suspend()

Remove software_suspend() and all its users since
pm_suspend(PM_SUSPEND_DISK) should be equivalent and there's no point in
having two interfaces for the same thing.

The patch also changes the valid_state function to return 0 (false) for
PM_SUSPEND_DISK when SOFTWARE_SUSPEND is not configured instead of
accepting it and having the whole thing fail later.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/init.h b/include/linux/init.h
index 9abf120..dbbdbd1 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -233,7 +233,7 @@
 #define __obsolete_setup(str) 			/* nothing */
 #endif
 
-/* Data marked not to be saved by software_suspend() */
+/* Data marked not to be saved by software suspend */
 #define __nosavedata __attribute__ ((__section__ (".data.nosave")))
 
 /* This means "can be init if no module support, otherwise module load