rbutil: include nwztools source in release tarball

Change-Id: Ic6d998441fb532a914eea2838fdc0d196f930bb2
diff --git a/utils/common/deploy-rbutil.py b/utils/common/deploy-rbutil.py
index 6db45ee..5085f18 100755
--- a/utils/common/deploy-rbutil.py
+++ b/utils/common/deploy-rbutil.py
@@ -26,6 +26,7 @@
              "tools/ucl",
              "tools/rbspeex",
              "utils/imxtools",
+             "utils/nwztools",
              "lib/rbcodec/codecs/libspeex",
              "docs/COPYING",
              "docs/gpl-2.0.html",