input: remove zylonite touchscreen driver

The PXA zylonite platform was removed, so this driver has no
remaining users.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: linux-input@vger.kernel.org
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>