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/radeontools/default.nix

@@ -0,0 +1,25 @@
+{ lib, stdenv, fetchurl
+, autoreconfHook
+, pciutils
+, pkg-config
+, xorg
+}:
+
+stdenv.mkDerivation rec {
+  pname = "radeontool";
+  version = "1.6.3";
+
+  src = fetchurl {
+    url = "https://people.freedesktop.org/~airlied/radeontool/${pname}-${version}.tar.gz";
+    sha256 = "0mjk9wr9rsb17yy92j6yi16hfpa6v5r1dbyiy60zp4r125wr63za";
+  };
+
+  nativeBuildInputs = [ autoreconfHook pkg-config ];
+  buildInputs = [ xorg.libpciaccess ];
+
+  meta = with lib; {
+    description = "Lowlevel tools to tweak register and dump state on radeon GPUs";
+    homepage = "https://airlied.livejournal.com/";
+    license = licenses.zlib;
+  };
+}