We don't initialize click methods on devices with physical buttons. This model
is a special case, it's not a clickpad but it only has one button (because one
button is all you ever need and whatnot).
https://bugs.freedesktop.org/show_bug.cgi?id=99283
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
(cherry picked from commit f2f616a1fc)
