led blinking patches

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