ThunderX Panic after r368370

[Marcel Flores]

Hi All,

Looks like the ThunderX started panicking at boot after r368370:

https://reviews.freebsd.org/rS368370

From a verbose boot, it looks like it bails in gic0 redistributor setup(?):

gic0: CPU29 Re-Distributor woke up
gic0: CPU24 enabled CPU interface via system registers
gic0: CPU17 enabled CPU interface via system registers
gic0: CPU29 enabled CPU interface via system registers
done

Full Verbose boot: 
https://gist.github.com/mesflores/f026122495c8494d041bce04d30b15bb

I'm not really familiar with the details of the commit, but happy to test
anything if anyone has any ideas.

-Marcel