refpol: Add the "tun_socket" object class flask definitions

Add the new "tun_socket" class to the flask definitions.  The "tun_socket"
object class is used by the new TUN driver hooks which allow policy to control
access to TUN/TAP devices.

Signed-off-by: Paul Moore <paul.moore@hp.com>

policy/flask/access_vectors

@@ -251,6 +251,8 @@ inherits socket
 class unix_dgram_socket
 inherits socket
 
+class tun_socket
+inherits socket
 
 #
 # Define the access vector interpretation for process-related objects

policy/flask/security_classes

@@ -119,4 +119,6 @@ class x_application_data	# userspace
 # kernel services that need to override task security, e.g. cachefiles
 class kernel_service 
 
+class tun_socket
+
 # FLASK