microsoft/surface: Remove old kernel version

microsoft/surface/common/kernel/linux-surface/default.nix

@@ -0,0 +1,31 @@
+{ config, lib, pkgs, ... }:
+
+let
+  inherit (lib) mkIf mkOption;
+
+  inherit (pkgs.callPackage ../linux-package.nix { }) linuxPackage surfacePatches isVersionOf versionsOfEnum;
+
+  cfg = config.microsoft-surface;
+
+  version = "6.11.4";
+  kernelPatches = surfacePatches {
+    inherit version;
+    patchFn = ./patches.nix;
+  };
+  kernelPackages = linuxPackage {
+    inherit version kernelPatches;
+    sha256 = "0mcg1rrw9b0lwj88jkaw6ic2mks8xh8i92v90sbr2x35ljhb0m5x";
+    ignoreConfigErrors=true;
+  };
+
+in {
+  options.microsoft-surface.kernelVersion = mkOption {
+    type = versionsOfEnum version;
+  };
+
+  config = mkIf (isVersionOf cfg.kernelVersion version) {
+    boot = {
+      inherit kernelPackages;
+    };
+  };
+}