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/misc/mkgmap/update.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i bash -p curl common-updater-scripts
+
+set -euo pipefail
+
+version=$(curl -s $2 | sed -n 's#.*<span data-bind="text: current().version">\(.*\)</span>.*#\1#p')
+update-source-version $1 "$version"