Adds an ext-tile config flag to host new tiling

Change-Id: I6c3bf5545c42030b484a8aaf434b63bd409a0487
diff --git a/configure b/configure
index 5eec2a1..e7eb152 100755
--- a/configure
+++ b/configure
@@ -282,6 +282,7 @@
     ans
     loop_restoration
     ext_partition
+    ext_tile
     obmc
     affine_motion
 "