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/rfkill/udev.nix

@@ -0,0 +1,56 @@
+{ lib, stdenv, substituteAll }:
+
+# Provides a facility to hook into rfkill changes.
+#
+# Exemplary usage:
+#
+# Add this package to udev.packages, e.g.:
+#   udev.packages = [ pkgs.rfkill_udev ];
+#
+# Add a hook script in the managed etc directory, e.g.:
+#   etc."rfkill.hook" = {
+#     mode = "0755";
+#     text = ''
+#       #!${pkgs.runtimeShell}
+#
+#       if [ "$RFKILL_STATE" -eq "1" ]; then
+#         exec ${config.system.build.upstart}/sbin/initctl emit -n antenna-on
+#       else
+#         exec ${config.system.build.upstart}/sbin/initctl emit -n antenna-off
+#       fi
+#     '';
+#   }
+
+# Note: this package does not need the binaries
+# in the rfkill package.
+
+let
+  rfkillHook =
+    substituteAll {
+      inherit (stdenv) shell;
+      isExecutable = true;
+      src = ./rfkill-hook.sh;
+    };
+in stdenv.mkDerivation {
+  name = "rfkill-udev";
+
+  dontUnpack = true;
+  dontBuild = true;
+
+  installPhase = ''
+    mkdir -p "$out/etc/udev/rules.d/";
+    cat > "$out/etc/udev/rules.d/90-rfkill.rules" << EOF
+      SUBSYSTEM=="rfkill", ATTR{type}=="wlan", RUN+="$out/bin/rfkill-hook.sh"
+    EOF
+
+    mkdir -p "$out/bin/";
+    cp ${rfkillHook} "$out/bin/rfkill-hook.sh"
+  '';
+
+  meta = with lib; {
+    homepage = "http://wireless.kernel.org/en/users/Documentation/rfkill";
+    description = "Rules+hook for udev to catch rfkill state changes";
+    platforms = platforms.linux;
+    license = licenses.mit;
+  };
+}