arm/dts: twl6030: Add DTS file for twl6030 PMIC

Add a dedicated DTS file for the twl6030 Power IC.
This chip is a big SoC that will be reused in a lot of various
OMAP4+ boards.

Note: This file is supposed to be included in a board DTS that will
create the twl node in order to allow the &twl reference to work.

Exmaple:
...
&i2c1 {
    twl: twl@48 {
        reg = <0x48>;
        interrupts = <0 7 4>;
        interrupt-controller;
        interrupt-parent = <&gic>;
    };
};

/include/ "twl6030.dtsi"
...
Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Rob Herring <rob.herring@calxeda.com>

arch/arm/boot/dts/twl6030.dtsi

+/*
+ * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * Integrated Power Management Chip
+ * http://www.ti.com/lit/ds/symlink/twl6030.pdf
+ */
+&twl {
+	compatible = "ti,twl6030";
+	interrupt-controller;
+	#interrupt-cells = <1>;
+
+	rtc {
+		compatible = "ti,twl4030-rtc";
+		interrupts = <11>;
+	};
+};