1. Set input bits for direct keys codes
2. Set input bits for rotary encoder codes only if rotary
   encoder is enabled
3. Enable EV_REL only if rotary encoder is enabled and rel_codes
   are set up
Signed-off-by: Antonio Ospite <ao2@openezx.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>