[U-Boot] Booting on RK3399

[Mark Kettenis]

> From: Simon Glass <sjg at chromium.org>
> Date: Wed, 2 Jan 2019 20:37:45 -0700
> 
> > Haven't tested flashing eMMC with rkdeveloptool myself, but that
> > should work on the firefly as well.
> >
> > Another complication as that the serial console speed defaults to
> > 1500000 which isn't supported by all serial-to-USB chips and frankly
> 
> Yes I seem to have one that supports this, so this is fine.

Just be aware that you'll need to patch TF-A to configure the serial
port to 1500000 as well.  Probably just a matter of changing
RK3399_BAUDRATE in plat/rockchip/rk3399/rk3399_def.h.

Cheers,

Mark