unbreak linux v5.10 on x86_64 by disabling OF_OVERLAY (#405841)

        # enable support for device trees and overlays

        OF = option yes;

        OF_OVERLAY = option yes;

        # OF_OVERLAY breaks v5.10 on x86_64, see https://github.com/NixOS/nixpkgs/issues/403985

        OF_OVERLAY = lib.mkIf (!(lib.versionOlder version "5.15" && stdenv.hostPlatform.isx86_64)) (

          option yes

        );

        # Enable initrd support.

        BLK_DEV_INITRD = yes;