convert udp chardev to QemuOpts.

While being at it: create a new inet_dgram_opts() function for udp setup,
so udp can handle IPv6 now.

new cmd line syntax:
    -chardev udp,id=name,host=remotehost,port=remoteport,\
	localaddr=bindaddr,localport=bindport

Signed-off-by: Gerd Hoffmann <[email protected]>
Signed-off-by: Anthony Liguori <[email protected]>
diff --git a/qemu_socket.h b/qemu_socket.h
index 6ee9510..c253b32 100644
--- a/qemu_socket.h
+++ b/qemu_socket.h
@@ -41,6 +41,7 @@
                 int socktype, int port_offset);
 int inet_connect_opts(QemuOpts *opts);
 int inet_connect(const char *str, int socktype);
+int inet_dgram_opts(QemuOpts *opts);
 
 int unix_listen_opts(QemuOpts *opts);
 int unix_listen(const char *path, char *ostr, int olen);