sysfs: deprecated features are to help old tools not to confuse them

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Greg KH <gregkh@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>