sof-firmware: provide update script

pkgs/by-name/so/sof-firmware/package.nix

@@ -2,6 +2,7 @@
   lib,
   fetchurl,
   stdenvNoCC,
+  nix-update-script,
 }:
 
 stdenvNoCC.mkDerivation (finalAttrs: {
@@ -25,6 +26,8 @@ stdenvNoCC.mkDerivation (finalAttrs: {
     runHook postInstall
   '';
 
+  passthru.updateScript = nix-update-script { };
+
   meta = {
     changelog = "https://github.com/thesofproject/sof-bin/releases/tag/v${finalAttrs.version}";
     description = "Sound Open Firmware";