[Arm-netbook] A new MK802 failing to boot from SD

[Valery Yundin]

My Mele A1000 sometimes does not boot from SD card after reboot.
Sometimes it just hangs or does a few reboot cycles (as if kernel
panicked) and then eventually hangs.

The workaround which works for me is to unplug power and ethernet for
~5 min and try again, usually it boots then.

PS I have rootfs on USB disk so the issue could be unrelated.