hwmon: (lm63) Consider LM64 temperature offset

LM64 has 16 degrees Celsius temperature offset on all
remote sensor registers.
This was not considered When LM64 support was added to lm63.c.

Signed-off-by: Dirk Eibach <eibach@gdsys.de>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: stable@kernel.org