Add localversion to identify builds from this tree

Signed-off-by: Bob Copeland <me@bobcopeland.com>
diff --git a/localversion-wireless-testing b/localversion-wireless-testing
new file mode 100644
index 0000000..f128484
--- /dev/null
+++ b/localversion-wireless-testing
@@ -0,0 +1 @@
+-wt