1. Rotary encoder events can be configured either as relative events
as the legacy code does or as any specified key code, this is
useful on some platform which uses the rotary keys as
KEY_{UP/DOWN/LEFT/RIGHT}
2. Add support for direct keys, the corresponding keycodes for each
direct key can now be specified within the platform data
3. Remove the direct/rotary key detection code from the IRQ handler
to dedicated functions to improve readability
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>