[U-Boot] rockchip: rk3188: rock: adjust for SPL/TPL split

[Philipp Tomsich]

> With the changes to split SPL/TPL for the RK3368, I apparently missed
> some needed adjustments to the RK3188 Kconfig and rock_defconfig.
> 
> This fixes build-issues for the rock board after applying the RK3368
> enablement (and SPL/TPL) set that resulted from TPL_SERIAL_SUPPORT,
> TPL_ROCKCHIP_BACK_TO_BROM and TPL_TINY_MEMSET being separate symbols
> now.
> 
> Signed-off-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
> Reviewed-by: Simon Glass <sjg at chromium.org>
> ---
> 
>  arch/arm/mach-rockchip/Makefile       | 4 +++-
>  arch/arm/mach-rockchip/rk3188/Kconfig | 3 ---
>  configs/rock_defconfig                | 2 ++
>  lib/Kconfig                           | 9 +++++++++
>  4 files changed, 14 insertions(+), 4 deletions(-)
> 

Applied to u-boot-rockchip, thanks!