Revert "serial: of-serial: fetch line number from DT"

This reverts commit 1bd83245.

To quote Olof:
	This commit broke a whole lot of tegra boards in last night's
	-next here. In particular, I've been looking at
	tegra20-seaboard, which now doesn't boot with console any more.

Breaking existing systems is bad.
Reported-by: Olof Johansson <olof@lixom.net>
Cc: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/of_serial.c

@@ -102,10 +102,6 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 	if (of_property_read_u32(np, "fifo-size", &prop) == 0)
 		port->fifosize = prop;
 
-	/* Check for a fixed line number */
-	if ((ret = of_alias_get_id(np, "serial")) >= 0)
-		port->line = ret;
-
 	port->irq = irq_of_parse_and_map(np, 0);
 	port->iotype = UPIO_MEM;
 	if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {