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/tools/networking/gvpe/default.nix

@@ -0,0 +1,33 @@
+{ lib, stdenv, fetchurl, openssl, gmp, zlib, iproute2, nettools, pkg-config }:
+
+stdenv.mkDerivation rec {
+  pname = "gvpe";
+  version = "3.1";
+
+  src = fetchurl {
+    url = "https://ftp.gnu.org/gnu/gvpe/gvpe-${version}.tar.gz";
+    sha256 = "sha256-8evVctclu5QOCAdxocEIZ8NQnc2DFvYRSBRQPcux6LM=";
+  };
+
+  nativeBuildInputs = [ pkg-config ];
+  buildInputs = [ openssl gmp zlib ];
+
+  configureFlags = [
+    "--enable-tcp"
+    "--enable-http-proxy"
+    "--enable-dns"
+  ];
+
+  postPatch = ''
+    sed -e 's@"/sbin/ifconfig.*"@"${iproute2}/sbin/ip link set $IFNAME address $MAC mtu $MTU"@' -i src/device-linux.C
+    sed -e 's@/sbin/ifconfig@${nettools}/sbin/ifconfig@g' -i src/device-*.C
+  '';
+
+  meta = with lib; {
+    description = "A protected multinode virtual network";
+    homepage = "http://software.schmorp.de/pkg/gvpe.html";
+    maintainers = [ maintainers.raskin ];
+    platforms = with platforms; linux ++ freebsd;
+    license = licenses.gpl2;
+  };
+}