char/agp: add another Ironlake host bridge

This seems to come on Gigabyte H55M-S2V and was discovered through the
https://bugs.freedesktop.org/show_bug.cgi?id=50381 debugging.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=50381


Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>