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/development/tools/knightos/scas/default.nix

@@ -0,0 +1,39 @@
+{ fetchFromGitHub, lib, stdenv, cmake, buildPackages, asciidoc, libxslt }:
+
+let
+  isCrossCompiling = stdenv.hostPlatform != stdenv.buildPlatform;
+in
+
+stdenv.mkDerivation rec {
+  pname = "scas";
+  version = "0.5.5";
+
+  src = fetchFromGitHub {
+    owner = "KnightOS";
+    repo = "scas";
+    rev = version;
+    sha256 = "sha256-JGQE+orVDKKJsTt8sIjPX+3yhpZkujISroQ6g19+MzU=";
+  };
+
+  cmakeFlags = [ "-DSCAS_LIBRARY=1" ];
+  postPatch = ''
+    substituteInPlace CMakeLists.txt \
+      --replace "TARGETS scas scdump scwrap" "TARGETS scas scdump scwrap generate_tables"
+  '';
+  strictDeps = true;
+
+  depsBuildBuild = lib.optionals isCrossCompiling [ buildPackages.knightos-scas ];
+  nativeBuildInputs = [ asciidoc libxslt.bin cmake ];
+  postInstall = ''
+    cd ..
+    make DESTDIR=$out install_man
+  '';
+
+  meta = with lib; {
+    homepage    = "https://knightos.org/";
+    description = "Assembler and linker for the Z80";
+    license     = licenses.mit;
+    maintainers = with maintainers; [ siraben ];
+    platforms   = platforms.all;
+  };
+}