Input: cyttsp - I2C driver split into two modules

Existing I2C code is for TrueTouch Gen3 devices

TrueTouch Gen4 device is using same protocol, will split driver into
two pieces to use common code with both drivers.

Read/Write functions parameter list modified, since shared code will
be used by two separate drivers and these drivers are not sharing same
structs, parameters updated to use common structures.

Signed-off-by: Ferruh Yigit <fery@cypress.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Javier Martinez Canillas <javier@dowhile0.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>