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/default.nix

@@ -0,0 +1,23 @@
+{ lib, stdenv, rpm, cpio, substituteAll }:
+
+stdenv.mkDerivation {
+  name = "rpmextract";
+
+  buildCommand = ''
+    install -Dm755 $script $out/bin/rpmextract
+  '';
+
+  script = substituteAll {
+    src = ./rpmextract.sh;
+    isExecutable = true;
+    inherit rpm cpio;
+    inherit (stdenv) shell;
+  };
+
+  meta = with lib; {
+    description = "Script to extract RPM archives";
+    platforms = platforms.all;
+    license = licenses.gpl2;
+    maintainers = with maintainers; [ abbradar ];
+  };
+}

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