Revert "serial: Delete dead code for CIR serial ports"

This reverts commit 1104321a.

The code is not dead at all and breaks winbond-cir.

Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled
00:02: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
00:03: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a CIR port
lirc lirc0: lirc_dev: driver ir-lirc-codec (winbond-cir) registered at minor = 0
winbond-cir 00:03: Region 0x2f8-0x2ff already in use!
winbond-cir: probe of 00:03 failed with error -16
Signed-off-by: Sean Young <sean@mess.org>
Reviewed-by: Matthias Brugger <mbrugger@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_core.c

@@ -1043,13 +1043,24 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
 		if (up->dl_write)
 			uart->dl_write = up->dl_write;
 
+		if (uart->port.type != PORT_8250_CIR) {
 			if (serial8250_isa_config != NULL)
 				serial8250_isa_config(0, &uart->port,
 						&uart->capabilities);
 
-		ret = uart_add_one_port(&serial8250_reg, &uart->port);
+			ret = uart_add_one_port(&serial8250_reg,
+						&uart->port);
 			if (ret == 0)
 				ret = uart->port.line;
+		} else {
+			dev_info(uart->port.dev,
+				"skipping CIR port at 0x%lx / 0x%llx, IRQ %d\n",
+				uart->port.iobase,
+				(unsigned long long)uart->port.mapbase,
+				uart->port.irq);
+
+			ret = 0;
+		}
 	}
 	mutex_unlock(&serial_mutex);