fbdev: remove w100fb driver

The w100fb was used on various PXA based pocketpc machines,
all of which are now removed, so remove this dirver sd well.

Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>