Report 3-rd and 4-th fingers as first finger for Elan hw v.2 and v.3 as
Linux does. It should not affect gesture processing in current state as it
ignores finger coords on 3-finger tap detection but it should make evdev
reports looking more Linux-alike.

Reviewed by: gonzo
Approved by: gonzo
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D10266