Input: usbtouchscreen - support bigger iNexio touchscreens

Bigger Nexio touchscreens not only send more data but also the header
values are modified somewhat.  Fix the header (it's a guesswork but
it works at least on one 46" touchscreen with 2.00SMS firmware) and
also increase rept_size.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>