[PATCH] intelfb: extend partial support of i915G to include i915GM

Add partial support for GMA900 within the i915GM chipset.

Signed-off-by: Scott MacKenzie <irrational@poboxes.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>