serial: mxs-auart: Allow device tree probing

Allow device tree probing.

Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: <linux-serial@vger.kernel.org>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Subodh Nijsure <snijsure@grid-net.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt

@@ -0,0 +1,27 @@
+* Freescale MXS Application UART (AUART)
+
+Required properties:
+- compatible : Should be "fsl,<soc>-auart". The supported SoCs include
+  imx23 and imx28.
+- reg : Address and length of the register set for the device
+- interrupts : Should contain the auart interrupt numbers
+
+Example:
+auart0: serial@8006a000 {
+	compatible = "fsl,imx28-auart", "fsl,imx23-auart";
+	reg = <0x8006a000 0x2000>;
+	interrupts = <112 70 71>;
+};
+
+Note: Each auart port should have an alias correctly numbered in "aliases"
+node.
+
+Example:
+
+aliases {
+	serial0 = &auart0;
+	serial1 = &auart1;
+	serial2 = &auart2;
+	serial3 = &auart3;
+	serial4 = &auart4;
+};