modules.d: add a module for early fan control on PowerPC Macs

modules.d: add a module for early fan control on PowerPC Macs

The goal of this module is to enable automatic loading of the
thermal/fan control modules on PowerPC based Macs, as on some
modular kernel configurations this will not happen automatically
which will result in the fans spinning up to 100% until they are
manually loaded.

This is especially a problem in live systems where it takes some
time to boot up and the spin-up happens before the system even
leaves initramfs.