powerpc/e6500: Add architecture categories for e6500 cores

-also define a binding for fsl,eref-* properties

Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

Documentation/devicetree/bindings/powerpc/fsl/cpus.txt

@@ -0,0 +1,22 @@
+===================================================================
+Power Architecture CPU Binding
+Copyright 2013 Freescale Semiconductor Inc.
+
+Power Architecture CPUs in Freescale SOCs are represented in device trees as
+per the definition in ePAPR.
+
+In addition to the ePAPR definitions, the properties defined below may be
+present on CPU nodes.
+
+PROPERTIES
+
+   - fsl,eref-*
+        Usage: optional
+        Value type: <empty>
+        Definition: The EREF (EREF: A Programmer.s Reference Manual for
+	Freescale Power Architecture) defines the architecture for Freescale
+	Power CPUs.  The EREF defines some architecture categories not defined
+	by the Power ISA.  For these EREF-specific categories, the existence of
+	a property named fsl,eref-[CAT], where [CAT] is the abbreviated category
+	name with all uppercase letters converted to lowercase, indicates that
+	the category is supported by the implementation.