TTY: add tty_port_tty_wakeup helper

It allows for cleaning up on a considerable amount of places. They did
port_get, wakeup, kref_put. Now the only thing needed is to call
tty_port_tty_wakeup which does exactly that.

One exception is ifx6x60 where tty_wakeup was open-coded. We now call
tty_wakeup properly there.

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 b7ff59d..8bb757c 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -233,6 +233,22 @@
 EXPORT_SYMBOL(tty_port_hangup);
 
 /**
+ * tty_port_tty_wakeup - helper to wake up a tty
+ *
+ * @port: tty port
+ */
+void tty_port_tty_wakeup(struct tty_port *port)
+{
+	struct tty_struct *tty = tty_port_tty_get(port);
+
+	if (tty) {
+		tty_wakeup(tty);
+		tty_kref_put(tty);
+	}
+}
+EXPORT_SYMBOL_GPL(tty_port_tty_wakeup);
+
+/**
  *	tty_port_carrier_raised	-	carrier raised check
  *	@port: tty port
  *