Input: msg2638 - set max finger number and irqhandler from driver data

This will allow us to add other MStar touchscreen variants' support.
No functional change.

Signed-off-by: Vincent Knecht <vincent.knecht@mailoo.org>
Link: https://lore.kernel.org/r/20221110171952.34207-2-vincent.knecht@mailoo.org


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>