platform/x86: Add Asus TF103C dock driver

Add a driver for the keyboard, touchpad and USB port of
the keyboard dock for the Asus TF103C 2-in-1 tablet.

This keyboard dock has its own I2C attached embedded controller
and the keyboard and touchpad are also connected over I2C,
instead of using the usual USB connection. This means that the
keyboard dock requires this special driver to function.

Cc: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Cc: Ion Agorria <ion@agorria.com>
Cc: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20211226141849.156407-1-hdegoede@redhat.com