HID: hid-multitouch: add support for Elo TouchSystems 2515 IntelliTouch Plus

This patch adds support for Elo TouchSystems 2515 IntelliTouch Plus
that can be found in Lenovo A700 all-in-one.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@enac.fr>
Tested-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --cc drivers/hid/Kconfig
Simple merge

diff --cc drivers/hid/hid-core.c
Simple merge

diff --cc drivers/hid/hid-ids.h
Simple merge

diff --cc drivers/hid/hid-multitouch.c
Simple merge