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/os-specific/windows/mingw-w64/pthreads.nix

@@ -0,0 +1,16 @@
+{ stdenv, mingw_w64 }:
+
+stdenv.mkDerivation {
+  name = "${mingw_w64.name}-pthreads";
+  inherit (mingw_w64) src meta;
+
+  configureFlags = [
+    # Rustc require 'libpthread.a' when targeting 'x86_64-pc-windows-gnu'.
+    # Enabling this makes it work out of the box instead of failing.
+    "--enable-static"
+  ];
+
+  preConfigure = ''
+    cd mingw-w64-libraries/winpthreads
+  '';
+}