TTY: provide drivers with tty_port_install

This will be used in tty_ops->install to set tty->port (and to call
tty_standard_install).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index bf6e238..1ac8abf 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -413,6 +413,14 @@
 }
 EXPORT_SYMBOL(tty_port_close);
 
+int tty_port_install(struct tty_port *port, struct tty_driver *driver,
+		struct tty_struct *tty)
+{
+	tty->port = port;
+	return tty_standard_install(driver, tty);
+}
+EXPORT_SYMBOL_GPL(tty_port_install);
+
 int tty_port_open(struct tty_port *port, struct tty_struct *tty,
 							struct file *filp)
 {