hwmon: add driver for the hwmon parts of qnap-mcu devices

The MCU can be found on network-attached-storage devices made by QNAP
and provides access to fan control including reading back its RPM as
well as reading the temperature of the NAS case.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20241107114712.538976-8-heiko@sntech.de


Signed-off-by: Lee Jones <lee@kernel.org>