Added libfilterfw to core.mk.

Change-Id: Idb4c50bec8ae4328849736a7a120343276b45766
diff --git a/target/product/core.mk b/target/product/core.mk
index e9c8cbc..85559d4 100644
--- a/target/product/core.mk
+++ b/target/product/core.mk
@@ -66,6 +66,7 @@
     libstagefright_soft_vorbisdec \
     libstagefright_soft_vpxdec \
     libwilhelm \
+    libfilterfw \
     libz \
     wpa_supplicant.conf \
     Browser \