remove software_suspend()

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 <[email protected]>
Acked-by: "Rafael J. Wysocki" <[email protected]>
Cc: Pavel Machek <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>