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/linux/vm-tools/default.nix

@@ -0,0 +1,16 @@
+{ lib, stdenv, linux }:
+
+stdenv.mkDerivation {
+  pname = "vm-tools";
+  inherit (linux) version src;
+
+  makeFlags = [ "sbindir=${placeholder "out"}/bin" ];
+
+  preConfigure = "cd tools/vm";
+
+  meta = with lib; {
+    inherit (linux.meta) license platforms;
+    description = "Set of virtual memory tools";
+    maintainers = [ maintainers.evils ];
+  };
+}