[SERIAL] Pass device pointer through to tty_register_device.

This allows drivers to pass their struct device through to
tty_register_device, which in turn allows sysfs to show which
device and driver owns the UART.

drivers/serial/serial_core.c

@@ -2227,7 +2227,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
 	 * Register the port whether it's detected or not.  This allows
 	 * setserial to be used to alter this ports parameters.
 	 */
-	tty_register_device(drv->tty_driver, port->line, NULL);
+	tty_register_device(drv->tty_driver, port->line, port->dev);
 
  out:
 	up(&port_sem);

include/linux/serial_core.h

@@ -97,6 +97,7 @@
 struct uart_port;
 struct uart_info;
 struct serial_struct;
+struct device;
 
 /*
  * This structure describes all the operations that can be
@@ -218,6 +219,7 @@ struct uart_port {
 	unsigned int		custom_divisor;
 	unsigned int		line;			/* port index */
 	unsigned long		mapbase;		/* for ioremap */
+	struct device		*dev;			/* parent device */
 	unsigned char		hub6;			/* this should be in the 8250 driver */
 	unsigned char		unused[3];
 };