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/perl-modules/expression-generator/grab-url.sh

@@ -0,0 +1,19 @@
+#! /bin/sh
+
+source lib-cache.sh
+
+get_file() {
+    url="$1";
+
+    if [ -n "$url" ]; then
+        curl "$1";
+    else
+        echo -n;
+    fi;
+}
+
+url="$1";
+name="$2";
+name=${name:-$(basename "$url")}
+
+cached_output get_file "${name%%.*}" "$url" "${name#*.}"