Finally add the third PowerBook Wallstreet 233MHz model to the list of
known display resolutions.

Without this change, a 640x480 video mode is used.  A workaround so far was
to boot with 'video=atyfb:vmode:14'
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Solomon Peachy <pizza@shaftnet.org>
Cc: James Simmons <jsimmons@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>