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/tools/archivers/rpmextract/rpmextract.sh

@@ -0,0 +1,10 @@
+#!@shell@ -e
+
+if [ "$1" = "" ]; then
+  echo "usage: rpmextract package_name..." 1>&2
+  exit 1
+fi
+
+for i in "$@"; do
+  @rpm@/bin/rpm2cpio "$i" | @cpio@/bin/cpio -idv
+done