uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

pkgs/applications/video/epgstation/update.nix

@@ -0,0 +1,63 @@
+{ pname
+, version
+, homepage
+, lib
+, gitUpdater
+, writers
+, jq
+, yq
+}:
+
+let
+  updater = gitUpdater {
+    inherit pname version;
+    attrPath = lib.toLower pname;
+    rev-prefix = "v";
+  };
+  updateScript = builtins.elemAt updater 0;
+  updateArgs = map (lib.escapeShellArg) (builtins.tail updater);
+in writers.writeBash "update-epgstation" ''
+  set -euxo pipefail
+
+  # bump the version
+  ${updateScript} ${lib.concatStringsSep " " updateArgs}
+
+  cd "${toString ./.}"
+
+  # Get the path to the latest source. Note that we can't just pass the value
+  # of epgstation.src directly because it'd be evaluated before we can run
+  # updateScript.
+  SRC="$(nix-build ../../../.. --no-out-link -A epgstation.src)"
+  if [[ "${version}" == "$(${jq}/bin/jq -r .version "$SRC/package.json")" ]]; then
+    echo "[INFO] Already using the latest version of ${pname}" >&2
+    exit
+  fi
+
+  # Regenerate package.json from the latest source.
+  ${jq}/bin/jq '. + {
+      dependencies: (.dependencies + .devDependencies),
+    } | del(.devDependencies, .main, .scripts)' \
+    "$SRC/package.json" \
+    > package.json
+  ${jq}/bin/jq '. + {
+      dependencies: (.dependencies + .devDependencies),
+    } | del(.devDependencies, .main, .scripts)' \
+    "$SRC/client/package.json" \
+    > client/package.json
+
+  # Regenerate node packages to update the pre-overriden epgstation derivation.
+  # This must come *after* package.json has been regenerated.
+  pushd ../../../development/node-packages
+  ./generate.sh
+  popd
+
+  # Generate default streaming settings for the nixos module.
+  pushd ../../../../nixos/modules/services/video/epgstation
+  ${yq}/bin/yq -j '{ urlscheme , stream }' \
+    "$SRC/config/config.yml.template" \
+    > streaming.json
+
+  # Fix generated output for EditorConfig compliance
+  printf '\n' >> streaming.json  # rule: insert_final_newline
+  popd
+''