The LED's on after kernel is loaded, while starting up does not work.
           pmx_led_sys_green: pmx-led-sys-green {
                marvell,pins = "mpp28";
                marvell,function = "gpio";
                linux,default-trigger = "heartbeat";
                brightness = <255>;
            };
I first tried default-trigger, then I added brightness additionally
but LED's wont turn on.

Can you manually turn the LED on, using /sys/class/led/.../brightness?
It could be we have the wrong GPIO line for the led. It would be good
if you could test them all, not just this one led.

There is no sata hdd trigger and nand-disk does not trigger on sata
hdd activity.

They are out of tree patches. There was some discussion about SATA led
activity maybe 6 to 9 months ago. Maybe you can see why the suggested
patches got rejected. If i remember correctly, it was because they are
in the hot path.

   Andrew