Presently auto-dump option finds DDR base addresses from
statically defined per target meta data in boards.py. This
leads to auto-dump feature fail on different targets, say
with different DDR base and size.

Add support to parse DDR base addresses from load.cmm,
dump_info.txt or ramdump_msg.txt which ever is available in
that order. Fall-back to conventional static populated data
in boards.py if none of them is available.

Change-Id: Ie4ac4f281e92c9b527de17fa665c9cd6c3d5d384