Added skeleton for VP9 denoiser

Change-Id: Iccf6ede4c4f85646b0f8daec47050ce93e267c90

configure

diff --git a/configure b/configure
index 800553e..9a7de73 100755
--- a/configure
+++ b/configure
@@ -272,6 +272,7 @@
     alpha
     multiple_arf
     spatial_svc
+    denoising
 "
 CONFIG_LIST="
     external_build