[U-Boot] [U-Boot, v2, 05/19] rockchip: Add mention of other boards

[Philipp Tomsich]

> At present some Rockchip SoCs and boards are not mentioned in the README.
> So that people can see which SoCs are supported, expand the list to
> include everything.
> 
> Signed-off-by: Simon Glass <sjg at chromium.org>
> Reviewed-by: Kever Yang <kever.yang at rock-chips.com>
> ---
> 
> Changes in v2:
> - Mention EVB RV1108
> - Fix the name of the firefly-rk3399 defconfig
> 
>  doc/README.rockchip | 44 ++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 42 insertions(+), 2 deletions(-)
> 

Reviewed-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>