Input: add support for Cypress PS/2 Trackpads

This driver, submitted on behalf of Cypress Semiconductor Corporation and
additional contributors, provides support for the Cypress PS/2 Trackpad.

Original code contributed by Dudley Du (Cypress Semiconductor Corporation),
modified by Kamal Mostafa and Kyle Fazzari.

BugLink: http://launchpad.net/bugs/978807



Signed-off-by: Dudley Du <dudl@cypress.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kyle Fazzari <git@status.e4ward.com>
Signed-off-by: Mario Limonciello <mario_limonciello@dell.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Herton Krzesinski <herton.krzesinski@canonical.com>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Reviewed-by: Dudley Du <dudl@cypress.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>