LP55xx family devices have internal three program engines which are used for
loading LED patterns. To maintain legacy device attributes, specific data
structure is used, 'mode' and 'led_mux'. The mode is used for showing/storing
current engine mode such like disabled, load and run. Then led_mux is used for
showing/storing current output LED selection.

This is only for LP5523/55231.
Signed-off-by: Milo Kim <milo.kim@ti.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>