Add an example configuration for an end to end transparent clock.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>

E2E-TC.cfg

@@ -0,0 +1,13 @@
+#
+# End to End Transparent Clock example configuration containing
+# those attributes which differ from the defaults.  See the file,
+# default.cfg, for the complete list of available options.
+#
+[global]
+priority1		254
+free_running		1
+freq_est_interval	3
+tc_spanning_tree	1
+summary_interval	1
+clock_type		E2E_TC
+network_transport	L2