obj: add read() and write() object callbacks

include/socks/tty.h

@@ -3,6 +3,7 @@
 
 #include <socks/status.h>
 #include <socks/queue.h>
+#include <socks/object.h>
 #include <stdint.h>
 
 /* The TTY system.
@@ -58,6 +59,8 @@ enum tty_scroll_dir {
 typedef uint64_t tty_attrib_t;
 
 struct tty_driver {
+	struct object tty_base;
+
 	char tty_name[16];
 	enum tty_driver_type tty_type;
 	struct queue_entry tty_list;