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/tools/graphics/pikchr/default.nix

@@ -0,0 +1,39 @@
+{ lib
+, stdenv
+, fetchurl
+}:
+
+stdenv.mkDerivation {
+  pname = "pikchr";
+  # To update, use the last check-in in https://pikchr.org/home/timeline?r=trunk
+  version = "unstable-2022-01-30";
+
+  src = fetchurl {
+    url = "https://pikchr.org/home/tarball/5db3aa1d294dcd16/pikchr.tar.gz";
+    sha256 = "sha256-xnT2oOx4LK9CElXeAuQIKlu6WvMB8Nv5+2kBzWQ5Gpc=";
+  };
+
+  # can't open generated html files
+  postPatch = ''
+    substituteInPlace Makefile --replace open "test -f"
+  '';
+
+  makeFlags = [ "CC=${stdenv.cc.targetPrefix}cc" ];
+
+  installPhase = ''
+    install -Dm755 pikchr $out/bin/pikchr
+    install -Dm755 pikchr.out $out/lib/pikchr.o
+    install -Dm644 pikchr.h $out/include/pikchr.h
+  '';
+
+  doCheck = true;
+  checkTarget = "test";
+
+  meta = with lib; {
+    description = "A PIC-like markup language for diagrams in technical documentation";
+    homepage = "https://pikchr.org";
+    license = licenses.bsd0;
+    maintainers = with maintainers; [ fgaz ];
+    platforms = platforms.all;
+  };
+}