hwmon: (gsc-hwmon) Scale temperature to millidegrees

The GSC registers report temperature in decidegrees celcius so we
need to scale it to represent the hwmon sysfs API of millidegrees.

Cc: stable@vger.kernel.org
Fixes: 3bce5377

 ("hwmon: Add Gateworks System Controller support")
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Link: https://lore.kernel.org/r/1598548824-16898-1-git-send-email-tharvey@gateworks.com


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