hwmon: (dell-smm) Add cooling device support

Until now, only the temperature sensors where exported thru
the thermal subsystem. Export the fans as "dell-smm-fan[1-3]" too
to make them available as cooling devices.
Also update Documentation and fix a minor issue with the alphabetic
ordering of the includes.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20220410163935.7840-1-W_Armin@gmx.de


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