watchdog: davinci_wdt: add OF support

This adds OF support for davinci_wdt driver.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

Documentation/devicetree/bindings/watchdog/davinci-wdt.txt

@@ -0,0 +1,12 @@
+DaVinci Watchdog Timer (WDT) Controller
+
+Required properties:
+- compatible : Should be "ti,davinci-wdt"
+- reg : Should contain WDT registers location and length
+
+Examples:
+
+wdt: wdt@2320000 {
+	compatible = "ti,davinci-wdt";
+	reg = <0x02320000 0x80>;
+};