hwmon: (k10temp) Rework the temperature offset calculation

Some of the existing assumptions made do not scale properly
to new silicon in upcoming changes.  This commit should cause
no functional changes to existing silicon.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20210827201527.24454-2-mario.limonciello@amd.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>