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/applications/emulators/oberon-risc-emu/default.nix

@@ -0,0 +1,27 @@
+{ lib, stdenv, fetchFromGitHub, SDL2 }:
+
+stdenv.mkDerivation {
+  pname = "oberon-risc-emu";
+  version = "unstable-2020-08-18";
+
+  src = fetchFromGitHub {
+    owner = "pdewacht";
+    repo = "oberon-risc-emu";
+    rev = "26c8ac5737c71811803c87ad51f1f0d6e62e71fe";
+    sha256 = "1iriix3cfcpbkjb5xjb4ysh592xppgprwzp3b6qhwcx44g7kdvxq";
+  };
+
+  buildInputs = [ SDL2 ];
+
+  installPhase = ''
+    mkdir -p $out/bin
+    mv risc $out/bin
+  '';
+
+  meta = with lib; {
+    homepage    = "https://github.com/pdewacht/oberon-risc-emu/";
+    description = "Emulator for the Oberon RISC machine";
+    license     = licenses.isc;
+    maintainers = with maintainers; [ siraben ];
+  };
+}