[PATCH] mmconfig: Detect and support the E7520 and the 945G/GZ/P/PL

It seems that the only way to reliably support mmconfig in the presence of
funky biosen is to detect the hostbridge and read where the window is mapped
from its registers.  Do that for the E7520 and the 945G/GZ/P/PL for a start.

Signed-off-by: Olivier Galibert <galibert@pobox.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>