hwmon: (nct6775) Fix register for nct6799

Datasheet and variable name point to 0xe6

Fixes: aee395bb ("hwmon: (nct6755) Add support for NCT6799D")
Signed-off-by: Ahmad Khalifa <ahmad@khalifa.ws>
Link: https://lore.kernel.org/r/20230715145831.1304633-1-ahmad@khalifa.ws


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