linux: remove unused features

  modDirVersion ? null

, # An attribute set whose attributes express the availability of

  # certain features in this kernel.  E.g. `{iwlwifi = true;}'

  # certain features in this kernel.  E.g. `{ia32Emulation = true;}'

  # indicates a kernel that provides Intel wireless support.  Used in

  # NixOS to implement kernel-specific behaviour.

  features ? {}

  # Combine the `features' attribute sets of all the kernel patches.

  kernelFeatures = lib.foldr (x: y: (x.features or {}) // y) ({

    iwlwifi = true;

    efiBootStub = true;

    needsCifsUtils = true;

    netfilterRPFilter = true;

    ia32Emulation = true;

  } // features) kernelPatches;