serial: 8250: Add OF support for Xscale variant

This adds support for device tree probing for the Intel
Xscale 8250 variant needed to support device tree on
the Intel IXP4xx platforms.

Cc: devicetree@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/serial/8250.txt

@@ -21,6 +21,7 @@ Required properties:
 	- "altr,16550-FIFO128"
 	- "fsl,16550-FIFO64"
 	- "fsl,ns16550"
+	- "intel,xscale-uart"
 	- "ti,da830-uart"
 	- "aspeed,ast2400-vuart"
 	- "aspeed,ast2500-vuart"

drivers/tty/serial/8250/8250_of.c

@@ -327,6 +327,7 @@ static const struct of_device_id of_platform_serial_table[] = {
 	{ .compatible = "nvidia,tegra20-uart", .data = (void *)PORT_TEGRA, },
 	{ .compatible = "nxp,lpc3220-uart", .data = (void *)PORT_LPC3220, },
 	{ .compatible = "ralink,rt2880-uart", .data = (void *)PORT_RT2880, },
+	{ .compatible = "intel,xscale-uart", .data = (void *)PORT_XSCALE, },
 	{ .compatible = "altr,16550-FIFO32",
 		.data = (void *)PORT_ALTR_16550_F32, },
 	{ .compatible = "altr,16550-FIFO64",