fix kconfig override

the default kconfig should be in a config stanza, not in the
default attr of the options stanza, otherwise it gets overridden
completely instead of merged

default.nix

@@ -5,7 +5,8 @@ let
   overlay = import ./overlay.nix;
   nixpkgs = import <nixpkgs> ( device.system // {overlays = [overlay]; });
   config = (import ./merge-modules.nix) [
-    (import ./modules/base.nix { inherit device; })
+    ./modules/base.nix
+    ({ lib, ... } : { config = { inherit (device) kernel; }; })
     <liminix-config>
   ] nixpkgs.pkgs;
   finalConfig = config // {
@@ -15,7 +16,7 @@ let
     ;
   };
   squashfs = (import ./make-image.nix) nixpkgs finalConfig;
-  kernel = (import ./make-kernel.nix)  nixpkgs finalConfig;
+  kernel = (import ./make-kernel.nix)  nixpkgs finalConfig.kernel.config;
 in {
   outputs = {
     inherit squashfs kernel;

make-kernel.nix

@@ -24,6 +24,6 @@ in
 {
   vmlinux = callPackage ./make-vmlinux.nix {
     inherit tree;
-    inherit (config.kernel) config;# checkedConfig;
+    inherit config;
   };
 }

modules/base.nix

@@ -1,4 +1,3 @@
-{ device } :
 { lib, ...}:
 let inherit (lib) mkEnableOption mkOption types;
 in {
@@ -11,7 +10,6 @@ in {
     };
     kernel = mkOption {
       type = types.anything;
-      default = { inherit (device.kernel) config checkedConfig; };
     };
   };
 }