sc92031: sysfs link missing

Add missing sysfs device association. Compile tested only -ENOHW.

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=10380

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Cc: Cesar Eduardo Barros <cesarb@cesarb.net>
Cc: <tom@sharkbay.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>