The function get_raw_temp is local to the source and does not need to
be in global scope, so make it static.

Cleans up sparse warning:
drivers/hwmon/k10temp.c:149:14: warning: symbol 'get_raw_temp' was not
declared. Should it be static?
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>