Add in the usb-gadget package.

Change-Id: I578c107bd26a5c0373d07026a6f0bcc637740336
diff --git a/mendel.xml b/mendel.xml
index de7a13e..c3056bd 100644
--- a/mendel.xml
+++ b/mendel.xml
@@ -22,12 +22,13 @@
     <!-- END Misc Tools repos -->
 
     <!-- BEGIN Package repos -->
-    <project path="packages/mendel-minimal" name="aiy-board-tweaks" />
     <project path="packages/base-files" name="base-files" />
     <project path="packages/mdt-services" name="mdt-services" />
     <project path="packages/mendel-distro-info-data" name="mendel-distro-info-data" />
     <project path="packages/mendel-keyring" name="aiy-board-keyring" />
+    <project path="packages/mendel-minimal" name="aiy-board-tweaks" />
     <project path="packages/runonce" name="runonce" />
+    <project path="packages/usb-gadget" name="usb-gadget" />
 
     <!-- END Package repos -->