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/libraries/libiconv/setup-hook.sh

@@ -0,0 +1,8 @@
+# libiconv must be listed in load flags on non-Glibc
+# it doesn't hurt to have it in Glibc either though
+
+# See pkgs/build-support/setup-hooks/role.bash
+if [ -z "${dontAddExtraLibs-}" ]; then
+    getHostRole
+    export NIX_LDFLAGS${role_post}+=" -liconv"
+fi