Add device blueprint files to root build.

Test: built with a blueprint file in device/google/marlin
Change-Id: Ia820e6dd3d46b8f6f718b6fddedaa3f548b371fa
diff --git a/root.bp b/root.bp
index a1b1f6b..d1e8e3e 100644
--- a/root.bp
+++ b/root.bp
@@ -15,6 +15,7 @@
     "build/tools/*",
     "dalvik",
     "development/*",
+    "device/*/*",
     "external/*",
     "frameworks/av",
     "frameworks/base",