tap: add support for persistance

Type: feature

Change-Id: I775f53531972447ebae0d69b9e2dfeee84d115e5
Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>
diff --git a/src/vnet/devices/tap/tapv2.api b/src/vnet/devices/tap/tapv2.api
index 861fe17..ccbbe15 100644
--- a/src/vnet/devices/tap/tapv2.api
+++ b/src/vnet/devices/tap/tapv2.api
@@ -28,6 +28,8 @@
 enum tap_flags {
         TAP_FLAG_GSO = 1,
         TAP_FLAG_CSUM_OFFLOAD = 2,
+	TAP_FLAG_PERSIST = 4,
+	TAP_FLAG_ATTACH = 8,
 };
 
 /** \brief Initialize a new tap interface with the given parameters