Allow dhcpd to interact with ttys.

Bug: 8539042
Change-Id: I27bcc4a485b031d54e17b03164642821d546e62f
diff --git a/dhcp.te b/dhcp.te
index 10ab788..b806a89 100644
--- a/dhcp.te
+++ b/dhcp.te
@@ -29,3 +29,5 @@
 allow dhcp netd:{ netlink_kobject_uevent_socket netlink_route_socket netlink_nflog_socket } { read write };
 # netdev-bt-pan driver loading
 allow dhcp kernel:system module_request;
+
+allow dhcp tty_device:chr_file { rw_file_perms };