media: vivid: Add touch support

Support to emulate touch devices in vivid driver.
It generates touch patterns simulating single tap, double tap, triple
tap, move from left to right, zoom in, zoom out, palm press simulating
large area being pressed on screen, and simulating 16 different
simultaneous touch points.The values generated are based on
behavior of the rmi_f54 driver.

Signed-off-by: Vandana BN <bnvandana@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>