hwmon: (abituguru3) Convert to use devm_ functions

Convert to use devm_ functions to reduce code size and simplify the code.

Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Alistair John Strachan <alistair@devzero.co.uk>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>