HID: multitouch: Add quirk for VTL touch panels

VTL panels do not switch to the multitouch mode until the input mode
feature is read by the host. This should normally be done by
usbhid, but it looks like an other bug prevents usbhid to properly
retrieve the feature state. As a workaround, we force the reading of
the feature in mt_set_input_mode for such devices.

Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Mathieu Magnaudet <mathieu.magnaudet@enac.fr>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>