HID: 3m: Convert to MT slots

The Microtouch controller is capable of doing finger tracking on
up to 60 fingers. To reduce bandwidth and cpu usage, convert the
driver to use the MT slots protocol. On Stephane's suggestion, also
insert the additional copyright lines.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Acked-by: Stephane Chatty <chatty@enac.fr>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>