test: don't run the MT pressure test on devices without MT pressure
This test worked because on devices that don't use pressure the touches were
reset when BTN_TOUCH when to 0, triggering the 'ignore fake fingers when no
real fingers are down' behavior. But this is a different code path than the
pressure handling, so let's separate those tests.
Signed-off-by:
Peter Hutterer <peter.hutterer@who-t.net>