hwmon: (ad7314) Add 'name' sysfs attribute

commit 3ceefe4319636d89d4bdf40dca9471970f942e4f upstream.

The 'name' sysfs attribute is mandatory for hwmon devices, but was missing
in this driver.

Cc: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>