wmt(4): Reapply r358872 (by hselasky) modified to use
maximal input report size instead of wMaxPacketSize.
If the USB frame length is set to 1024 bytes, WMT_BSIZE, the EETI controller
will pack multiple touch events in the packet and the current code will only
process the first touch event.
As a result some important events are lost like releasing the finger from the
Use the maximal input report size as buffer size instead.
Tested by: Oskar Holmlund <email@example.com>, wulf
MFC after: 3 days
Discussed with: hselasky