qc71_laptop: add updateScript

pkgs/os-specific/linux/qc71_laptop/default.nix

@@ -4,6 +4,7 @@
   fetchFromGitHub,
   kernel,
   kernelModuleMakeFlags,
+  nix-update-script,
 }:
 
 stdenv.mkDerivation rec {
@@ -30,6 +31,10 @@ stdenv.mkDerivation rec {
     runHook postInstall
   '';
 
+  passthru.updateScript = nix-update-script {
+    extraArgs = [ "--version=branch" ];
+  };
+
   meta = with lib; {
     description = "Linux driver for QC71 laptop";
     homepage = "https://github.com/pobrn/qc71_laptop/";