hwmon: Discard useless I2C driver IDs

Many I2C hwmon drivers define a driver ID but no other code references
these, meaning that they are useless. Discard them, along with a few
IDs which are defined but never used at all.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>