Input: ALPS - suppress message about 'Unknown touchpad'

When we fail to match data returned by E7 and EC reports we state that we
found "Unknown ALPS touchpad" whereas it is most likely it is not ALPS
touchpad at all. Change wording a bit and reduce the message to debug so
that it does not litter users logs and confuse them.

Reported-by: Paul Menzel <paulepanter@users.sourceforge.net>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>