ddr: a80x0: add DDR 32-bit mode support

This commit introduces 32-bit DDR topology map initialization.
For that purpose a new DDR32 build flag is added, with
according documentation update.

Change-Id: I169ff358c2923afd984e27bc126dc551dcaefc01
Signed-off-by: Alex Leibovich <alexl@marvell.com>
diff --git a/docs/plat/marvell/armada/build.rst b/docs/plat/marvell/armada/build.rst
index 1b60fc5..6f28721 100644
--- a/docs/plat/marvell/armada/build.rst
+++ b/docs/plat/marvell/armada/build.rst
@@ -194,6 +194,10 @@
     can interrupt UART recovery process). This MACRO definition is set in
     ``plat/marvell/armada/a8k/common/include/platform_def.h`` file.
 
+- DDR32
+    In order to work in 32bit DDR, instead of the default 64bit ECC DDR,
+    this flag should be set to 1.
+
 For more information about build options, please refer to the
 :ref:`Build Options` document.