Rearrange the kernels to make them self-defining

microsoft/surface/kernel/linux-package.nix

@@ -0,0 +1,23 @@
+{ lib,
+  buildLinux,
+  callPackage,
+  fetchurl,
+  linuxPackagesFor,
+}:
+
+let
+  inherit (lib) kernel recurseIntoAttrs;
+
+in {
+  repos = callPackage ../repos.nix {};
+
+  linuxPackage =
+    { version,
+      modDirVersion ? version,
+      ...
+    } @ args:
+    let
+      buildLinux' = buildLinux (args // { inherit modDirVersion; });
+      linuxPackagesFor' = linuxPackagesFor buildLinux';
+    in recurseIntoAttrs linuxPackagesFor';
+}