[POWERPC] Document the global utilities node define and example

Document the global utilities node define and example.
Signed-off-by: NRoy Zang <tie-fei.zang@freescale.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

Documentation/powerpc/booting-without-of.txt

@@ -51,6 +51,7 @@ Table of Contents
       h) Board Control and Status (BCSR)
       i) Freescale QUICC Engine module (QE)
       g) Flash chip nodes
+      k) Global Utilities Block
 
   VII - Specifying interrupt information for devices
     1) interrupts property
@@ -1790,6 +1791,33 @@ platforms are moved over to use the flattened-device-tree model.
  		partition-names = "fs\0firmware";
  	};
 
+   k) Global Utilities Block
+
+   The global utilities block controls power management, I/O device
+   enabling, power-on-reset configuration monitoring, general-purpose
+   I/O signal configuration, alternate function selection for multiplexed
+   signals, and clock control.
+
+   Required properties:
+
+    - compatible : Should define the compatible device type for
+      global-utilities.
+    - reg : Offset and length of the register set for the device.
+
+  Recommended properties:
+
+    - fsl,has-rstcr : Indicates that the global utilities register set
+      contains a functioning "reset control register" (i.e. the board
+      is wired to reset upon setting the HRESET_REQ bit in this register).
+
+    Example:
+
+	global-utilities@e0000 {	/* global utilities block */
+		compatible = "fsl,mpc8548-guts";
+		reg = <e0000 1000>;
+		fsl,has-rstcr;
+	};
+
    More devices will be defined as this spec matures.
 
 VII - Specifying interrupt information for devices