vnc: switch to QemuOpts, allow multiple servers

This patch switches vnc over to QemuOpts, and it (more or less
as side effect) allows multiple vnc server instances.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/include/ui/console.h b/include/ui/console.h
index 03358b4..8a4d671 100644
--- a/include/ui/console.h
+++ b/include/ui/console.h
@@ -332,12 +332,14 @@
 
 /* vnc.c */
 void vnc_display_init(const char *id);
-void vnc_display_open(const char *id, const char *display, Error **errp);
+void vnc_display_open(const char *id, Error **errp);
 void vnc_display_add_client(const char *id, int csock, bool skipauth);
 char *vnc_display_local_addr(const char *id);
 #ifdef CONFIG_VNC
 int vnc_display_password(const char *id, const char *password);
 int vnc_display_pw_expire(const char *id, time_t expires);
+QemuOpts *vnc_parse_func(const char *str);
+int vnc_init_func(QemuOpts *opts, void *opaque);
 #else
 static inline int vnc_display_password(const char *id, const char *password)
 {