Input: iqs7222 - add support for Azoteq IQS7222D

The vendor has introduced a new variant of silicon which is highly
similar to the existing IQS7222A, but with its independent sliders
essentially replaced with a single-contact trackpad.

Update the common driver to support this new device's register map
and report trackpad events. As with the IQS7222A, the new IQS7222D
can report both raw coordinates as well as gestures.

Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/ZKrpRh6RT6+6KrMQ@nixie71
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>