hwmon: (lm70) Add a name attribute

Add a name attribute to the lm70 devices. This is required for
libsensors to recognize them.

Also drop the "+" before the temperature value, even though it did
not cause problems to libsensors, other hardware monitoring drivers
don't print it, so it's more consistent that way.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Hans de Goede <j.w.r.degoede@hhs.nl>
Acked-by: Kaiwan <kaiwan@designergraphix.com>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>