Add custom kernel config to shrink the image size

modules/kernel/default.nix

@@ -0,0 +1,19 @@
+{ lib, pkgs, ... }:
+{
+  boot.kernelPackages =
+    let
+      version = "6.11.2";
+    in
+    pkgs.linuxPackagesFor (
+      pkgs.linuxManualConfig {
+        version = "${version}-patos1";
+        modDirVersion = version;
+        src = pkgs.fetchurl {
+          url = "https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-${version}.tar.xz";
+          hash = "sha256:ec9ef7a0b9cebb55940e1ef87a1f9e1004b10456a119dc386bb3e565b0d39c42";
+        };
+        configfile = ./generic.config;
+        allowImportFromDerivation = true;
+      }
+    );
+}