led_strip: ws2812: use k_usleep() for reset delay
led_strip: ws2812: use k_usleep() for reset delay

Since this driver is working reliably, let's use k_usleep() instead of
k_busy_wait() (as suggested in a TODO comment) to latch and reset the
LED strip controller.

Signed-off-by: Simon Guinot <3ab4e30ada880520f74922b979fc5ca34d9375bb@seagate.com>

galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr