input: PCAP2 based touchscreen driver

Touchscreen driver for the PCAP2 multi function device used in
Motorola EZX smartphones.

Signed-off-by: Daniel Ribeiro <drwyrm@gmail.com>
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>