[U-Boot] rockchip: rk3328: fix syscon id table

[Philipp Tomsich]

> syscon id table need a dummy member as NULL ending, or else system
> will panic while try to match a compatible in this table as a list.
> 
> Signed-off-by: Kever Yang <kever.yang at rock-chips.com>
> ---
> 
>  arch/arm/mach-rockchip/rk3328/syscon_rk3328.c | 1 +
>  1 file changed, 1 insertion(+)
> 

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