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/build-support/fetchnextcloudapp/default.nix

@@ -0,0 +1,32 @@
+{ stdenv, fetchurl, ... }:
+{ name
+, url
+, version
+, sha256
+, patches ? [ ]
+}:
+stdenv.mkDerivation {
+  name = "nc-app-${name}";
+  inherit version patches;
+
+  src = fetchurl {
+    inherit url sha256;
+  };
+
+  unpackPhase = ''
+    tar -xzpf $src
+  '';
+
+  installPhase = ''
+    approot="$(dirname $(dirname $(find -path '*/appinfo/info.xml' | head -n 1)))"
+
+    if [ -d "$approot" ];
+    then
+      mv "$approot/" $out
+      chmod -R a-w $out
+    else
+      echo "Could not find appinfo/info.xml"
+      exit 1;
+    fi
+  '';
+}