HID: usbhid: use generic hidinput_input_event()

HID core provides the same functionality as we do, so drop the custom
hidinput_input_event() handler.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>