[U-Boot] rockchip: dts: rk3399-evb: remove redundant gmac node

[Philipp Tomsich]

> There are two same gmac node, remove one.
> 
> Signed-off-by: Kever Yang <kever.yang at rock-chips.com>
> Reviewed-by: Simon Glass <sjg at chromium.org>
> ---
> 
>  arch/arm/dts/rk3399-evb.dts | 16 ----------------
>  1 file changed, 16 deletions(-)
> 

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