This keyboard has two modes: regular HID and a native mode, which is used
in Windows driver. Native mode disables (poor) middle mouse button
scrolling emulation and reports middle button and scrolling events with a
custom report ID, which could be better handled in the driver.

This commit adds functional button mapping and native scrolling support.

HID collection in Bluetooth mode for custom report ID=5 is broken and
is patched upon connection. The collection initially contains incorrect
Usage Minimum/Usage Maximum numbers and, more importantly, marks Input
as Variable, not Array, while reporting values as in Array.

The keyboard is very similar to Compact USB/Bluetooth Keyboard with
TrackPoint, that's why this patch reuses all of cptkbd functions, except
for input mapping.
Signed-off-by: Florian Klink <flokli@flokli.de>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>