HID: add new multitouch and digitizer contants

Added constants to hid.h for all digitizer usages (including the new multitouch
ones that are not yet in the official USB spec but are being pushed by Microsft
as described in their paper "Digitizer Drivers for Windows Touch and Pen-Based
Computers"). Updated hid-debug.c to support the new MT input constants such as
ABS_MT_POSITION_X.

Signed-off-by: Stephane Chatty <chatty@enac.fr>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>