Add support for the Intel Atom D400/500- and N400-series integrated

Add support for the Intel Atom D400/500- and N400-series integrated
northbridge. Also add support for the very similar Q963/965 northbridge.
Tested:
  D510: confirmed working, with MCHBAR enable code
  Q965: writes to bit 0 to enable MCHBAR access are ignored, all other functions work

Untested:
  D410/D525/N400: should be the same northbridge

Signed-off-by: Corey Osgood <corey.osgood@gmail.com>
Acked-by: Paul Menzel <paulepanter@users.sourceforge.net>
Acked-by: Stefan Reinauer <stepan@coresystems.de>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5673 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1