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/flashbench/default.nix

@@ -0,0 +1,31 @@
+{ lib, stdenv, fetchFromGitHub }:
+
+stdenv.mkDerivation {
+  pname = "flashbench-unstable";
+  version = "2020-01-23";
+
+  src = fetchFromGitHub {
+    owner = "bradfa";
+    repo = "flashbench";
+    rev = "d783b1bd2443812c6deadc31b081f043e43e4c1a";
+    sha256 = "045j1kpay6x2ikz8x54ph862ymfy1nzpbmmqpf3nkapiv32fjqw5";
+  };
+
+  installPhase = ''
+    runHook preInstall
+
+    install -d -m755 $out/bin $out/share/doc/flashbench
+    install -v -m755 flashbench $out/bin
+    install -v -m755 erase $out/bin/flashbench-erase
+    install -v -m644 README $out/share/doc/flashbench
+
+    runHook postInstall
+  '';
+
+  meta = with lib; {
+    description = "Testing tool for flash based memory devices";
+    homepage = "https://github.com/bradfa/flashbench";
+    platforms = platforms.linux;
+    license = licenses.gpl2Only;
+  };
+}