[PATCH] lib/crc16: added crc16 algorithm.

Add the crc16 routines, as used by w1 devices.

Signed-off-by: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>