dt-bindings: hwmon: Add nct7802 bindings

This change documents the device tree bindings for the Nuvoton
NCT7802Y driver.

Signed-off-by: Oskar Senft <osk@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211020164213.174597-1-osk@google.com


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