of_serial: Add UPF_FIXED_TYPE flag

This patch adds the UPF_FIXED_TYPE flag which will bypass the
8250's autoconfig probe for uart type. The uart type identified
by the of_serial's parse of the flat device tree will be utilized
as defined.

Signed-off-by: Dave Mitchell <dmitchell@amcc.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/drivers/serial/of_serial.c b/drivers/serial/of_serial.c
index 14f8fa9..3f2027c 100644
--- a/drivers/serial/of_serial.c
+++ b/drivers/serial/of_serial.c
@@ -67,7 +67,7 @@
 	port->type = type;
 	port->uartclk = *clk;
 	port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
-		| UPF_FIXED_PORT;
+		| UPF_FIXED_PORT | UPF_FIXED_TYPE;
 	port->dev = &ofdev->dev;
 	/* If current-speed was set, then try not to change it. */
 	if (spd)