Change the hwmon device name to something more generic as this
should be functional for both the s3c24xx and s3c64xx archs.

Since it has yet to have a driver, it is pretty safe to change
as there are no extant users.

Also add the necessary entry in devs.h which seems to have been
missed  out at somepoint.
Signed-off-by: NBen Dooks <ben@simtec.co.uk>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>