[U-Boot] Run a standalone application on a core other than 0

[João Fernandes]

As the subject says, I'm trying to run the "Hello world" standalone
application example on a core other than 0, on a Freescale QorIQ P4080.

I tried through the shell and programmatically by exporting cpu_release
function... nothing. My first thought was that only core 0 has register r2
with the address of the "global_data" structure, so I tried to set it on
the other cores, but still nothing. Help on this matter is highly
appreciated.

Regards,
João Fernandes