staging:iio:light:tsl2563 missing setting of id in get id function.

Signed-off-by: Maxin B. John <maxin.john@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>