Input: add accelerated touchscreen support for Marvell Zylonite

This patch implements accelerated touchscreen support for the Marvell
Zylonite development platform, supporting pen down interrupts and
continuous mode data transfers.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>