TTY: use tty_port_register_device

Currently we have no way to assign tty->port while performing tty
installation. There are two ways to provide the link tty_struct =>
tty_port. Either by calling tty_port_install from tty->ops->install or
tty_port_register_device called instead of tty_register_device when
the device is being set up after connected.

In this patch we modify most of the drivers to do the latter. When the
drivers use tty_register_device and we have tty_port already, we
switch to tty_port_register_device. So we have the tty_struct =>
tty_port link for free for those.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/ifx6x60.c

@@ -800,8 +800,8 @@ static int ifx_spi_create_port(struct ifx_spi_device *ifx_dev)
 	tty_port_init(pport);
 	pport->ops = &ifx_tty_port_ops;
 	ifx_dev->minor = IFX_SPI_TTY_ID;
-	ifx_dev->tty_dev = tty_register_device(tty_drv, ifx_dev->minor,
-					       &ifx_dev->spi_dev->dev);
+	ifx_dev->tty_dev = tty_port_register_device(pport, tty_drv,
+			ifx_dev->minor, &ifx_dev->spi_dev->dev);
 	if (IS_ERR(ifx_dev->tty_dev)) {
 		dev_dbg(&ifx_dev->spi_dev->dev,
 			"%s: registering tty device failed", __func__);