Wizpig: add servo overlay

Inherit Strago servo overlay configuration since Wizpig is based on
Strago.

BUG=chrome-os-partner:42916, chrome-os-partner:48059
TEST=run 'cros_workon --host start hdctools'
         'sudo emerge hdctools'
         'sudo servod --board=wizpig'

Change-Id: Id0b47c39d249d03a4c8f2645d3f09024a6882000
Signed-off-by: Kaiyen Chang <kaiyen.chang@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/306674
Reviewed-by: Shawn N <shawnn@chromium.org>
(cherry picked from commit b232f563e8b5c25a2bbc3f0162436840885eacd1)
Reviewed-on: https://chromium-review.googlesource.com/323661
Reviewed-by: Bernie Thompson <bhthompson@chromium.org>
diff --git a/servo/data/servo_wizpig_overlay.xml b/servo/data/servo_wizpig_overlay.xml
new file mode 100644
index 0000000..dcdb8e8
--- /dev/null
+++ b/servo/data/servo_wizpig_overlay.xml
@@ -0,0 +1,5 @@
+<root>
+  <include>
+    <name>servo_strago_overlay.xml</name>
+  </include>
+</root>