HID: multitouch: touchscreens also use confidence reports

According to [1] the confidence is used not only by touchpad devices,
but also by touchscreens.

[1] https://docs.microsoft.com/en-us/windows-hardware/design/component-guidelines/touchscreen-required-hid-top-level-collections



Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
[rebased]
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>