ARM: h1940: framebuffer configuration fix

Seems like a typo, wrong setup leads to broken image on ipaq screen.

Signed-off-by: Mike Solovyev <ms@sk.2-ch.org>
Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>