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
touchscreen.

Use the maximum maximum packet size as buffer size instead.

Submitted by: Oskar Holmlund <oskar.holmlund@ohdata.se>
PR: 244718
MFC after: 3 days
Sponsored by: Mellanox Technologies