led blinking patches

[Mikhail Kshevetskiy]

Hi Simon and all,

This patch series implements:
 * software led blinking (via cyclic functions)
 * add support of dts property to specify blinking of the led

v2 changes:
 * Drop sw_blink_state structure, move its necessary fields to
   led_uc_plat structure.
 * Add cyclic_info pointer to led_uc_plat structure. This
   simplify code a lot.
 * Remove cyclic function search logic. Not needed anymore.
 * Fix blinking period. It was twice large.
 * Other cleanups.

Thanks,
Mikhail Kshevetskiy