drm_hwcomposer: Implement release and retire fences using sw_sync

Once drm supports passing sync through, we'll move onto that.

Signed-off-by: Sean Paul <seanpaul@chromium.org>
Change-Id: I78bd5d380212b4aaec4b41dcba6cc882f1e5cc20
diff --git a/Android.mk b/Android.mk
index 6236c57..2a725f3 100644
--- a/Android.mk
+++ b/Android.mk
@@ -33,6 +33,7 @@
 	external/libdrm/include/drm \
 	external/stlport/stlport \
 	system/core/include/utils \
+	system/core/libsync \
 	system/core/libsync/include \
 
 LOCAL_CFLAGS :=