Hibernation: Clean up Kconfig (V2)

This cleans up the hibernation Kconfig and removes the need to
declare centrally which architectures support hibernation. All
architectures that currently support hibernation are modified
accordingly.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Paul Mackerras <paulus@samba.org>
Cc: Pavel Machek <pavel@suse.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>