hwmon: (tc654) Add thermal_cooling device support

hwmon: (tc654) Add thermal_cooling device support

Adds thermal_cooling device support to the tc654/tc655
driver. This make it possible to integrate it into a
device-tree supported thermal-zone node as a
cooling device.

I have been using this patch as part of the Netgear WNDR4700
Centria NAS Router support within OpenWrt since 2016.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Link: https://lore.kernel.org/r/20220213004733.2421193-1-chunkeey@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>