dt-bindings: input: iqs7222: Extend slider-mapped GPIO to IQS7222C

dt-bindings: input: iqs7222: Extend slider-mapped GPIO to IQS7222C

Although the IQS7222C does not offer slider gesture support, the
press/release event can still be mapped to any of the IQS7222C's
three GPIO pins. Update the binding to reflect this relationship.

Fixes: 44dc42d254bf ("dt-bindings: input: Add bindings for Azoteq IQS7222A/B/C")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/20220626072412.475211-10-jeff@labundy.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>