Documentation: arm: add URLs to public datasheets for the Marvell Armada XP SoC

Marvell has very recently released a public version of the "Functional
specifications" and "Hardware specifications" datasheets for the
Marvell Armada XP SoC. This allows contributors and developers not
under NDA with Marvell to get more details about this SoC than what
the current kernel code shows, and hopefully allows to improve the
support for this SoC in the mainline kernel, as well as in other
projects.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: NSebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: NAndrew Lunn <andrew@lunn.ch>
Link: https://lkml.kernel.org/r/1406227593-29749-2-git-send-email-thomas.petazzoni@free-electrons.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

Documentation/arm/Marvell/README

@@ -102,8 +102,7 @@ EBU Armada family
         MV78460
     NOTE: not to be confused with the non-SMP 78xx0 SoCs
     Product Brief: http://www.marvell.com/embedded-processors/armada-xp/assets/Marvell-ArmadaXP-SoC-product%20brief.pdf
-
-  No public datasheet available.
+    Functional Spec: http://www.marvell.com/embedded-processors/armada-xp/assets/ARMADA-XP-Functional-SpecDatasheet.pdf
 
   Core: Sheeva ARMv7 compatible