leds: bcm6358: Use bcm6358_led_set() in order to get rid of the lock

Replaces bcm6358_led_mode with bcm6358_led_set so we don't need to handle
the lock.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>