Add opensource/tarballs to prism.

Change-Id: Ib8cede83f2c9c76818a7132d557ffc5b69b6f4ba
diff --git a/prism.xml b/prism.xml
index c1154e4..30160d2 100644
--- a/prism.xml
+++ b/prism.xml
@@ -14,5 +14,6 @@
   <project name="vendor/google/catawampus"/>
   <project name="vendor/google/platform"/>
   <project name="vendor/marvell/application"/>
+  <project name="vendor/opensource/tarballs"/>
   <project name="vendor/opensource/toolbox" path="toolbox-for-linux"/>
 </manifest>