HID: logitech-hidpp: Add Wireless Touchpad T650 support

All the bits are now in place to add the support of the
Touchpad T650.
The creation/population of the input device is delayed until
the device is ready.

The T650 uses the special HID++ reporting protocol, so activate
this on connect.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Andrew de los Reyes <adlr@chromium.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>