HID: roccat: remove obsolete kone_abi_version sysfs attribute

The newest version of the accompanying userland tools cuts backward
compatibility and uses libudev to find its devices superseding the
quirky kone_abi_version sysfs attribute. Therefore it should be removed.

Signed-off-by: Stefan Achatz <erazor_de@users.sourceforge.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>