Turn on socket activation for rest-dbus

Defer starting of rest-dbus until a client connects.

Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/common/recipes-phosphor/rest-dbus/files/rest-dbus.socket b/common/recipes-phosphor/rest-dbus/files/rest-dbus.socket
new file mode 100644
index 0000000..89f99b8
--- /dev/null
+++ b/common/recipes-phosphor/rest-dbus/files/rest-dbus.socket
@@ -0,0 +1,8 @@
+[Unit]
+Description=DBUS introspecting REST server socket.
+
+[Socket]
+ListenStream=3000
+
+[Install]
+WantedBy=sockets.target