hwmon: (w83627ehf) Better fix for negative temperature values

It is more efficient to left-align 8-bit temperature values, so that
8-bit and 9-bit temperature values can be handled exactly the same way
in the rest of the code.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>