Documentation/EDAC: Add reference documents section for amd64_edac

This section used to be in amd64_edac.h. Move it here as it is a more
natural place to put all documentation-related info. Add links to the
BKDGs while at it.

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1443440671-2400-1-git-send-email-Aravind.Gopalakrishnan@amd.com


Signed-off-by: Borislav Petkov <bp@suse.de>