* the keyboard modules in all-hardware.nix are already defaults of
boot.initrd.availableKernelModules
* ide modules, hid_lenovo_tpkbd and scsi_wait_scan have been removed
because they're not available anymore
* i8042 was a duplicate (see few lines abowe)
Due the recent inclusion of broadcom-bt-firmware in enableAllFirmware,
it was required to set `nixpkgs.config.allowUnfree` to obtain the full
list. To make this dependency more explicit an assertion is added and an
alternative option `enableRedistributalFirmware` is provided to only
obtain firmware with an license allowing redistribution.
