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/build-support/emacs/trivial.nix

@@ -0,0 +1,29 @@
+# trivial builder for Emacs packages
+
+{ callPackage, lib, ... }@envargs:
+
+with lib;
+
+args:
+
+callPackage ./generic.nix envargs ({
+  buildPhase = ''
+    runHook preBuild
+
+    emacs -L . --batch -f batch-byte-compile *.el
+
+    runHook postBuild
+  '';
+
+  installPhase = ''
+    runHook preInstall
+
+    LISPDIR=$out/share/emacs/site-lisp
+    install -d $LISPDIR
+    install *.el *.elc $LISPDIR
+
+    runHook postInstall
+  '';
+}
+
+// args)