drivers/rtc/rtc-imxdi.c: add devicetree support

Add device tree support to the rtc-imxdi driver.

Signed-off-by: Roland Stigge <stigge@antcom.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/devicetree/bindings/rtc/imxdi-rtc.txt

@@ -0,0 +1,17 @@
+* i.MX25 Real Time Clock controller
+
+This binding supports the following chips: i.MX25, i.MX53
+
+Required properties:
+- compatible: should be: "fsl,imx25-rtc"
+- reg: physical base address of the controller and length of memory mapped
+  region.
+- interrupts: rtc alarm interrupt
+
+Example:
+
+rtc@80056000 {
+	compatible = "fsl,imx53-rtc", "fsl,imx25-rtc";
+	reg = <0x80056000 2000>;
+	interrupts = <29>;
+};