[U-Boot] [U-Boot, v3] rockchip: rk3288: Add reset reason detection

[Philipp Tomsich]

> Sometimes it's helpful to know the reset reason caused in the SoC.
> Add reset reason detection for the RK3288 SoC.
> This will set an environment variable which represents the reset reason.
> 
> Signed-off-by: Wadim Egorov <w.egorov at phytec.de>
> ---
> Changes in v3:
> - Fixed typo in commit message
> - Use enum for CRU_GLB_RST_ST register decoding
> 
> ---
>  arch/arm/include/asm/arch-rockchip/cru_rk3288.h | 12 +++++++++
>  arch/arm/mach-rockchip/rk3288-board.c           | 35 +++++++++++++++++++++++++
>  2 files changed, 47 insertions(+)
> 

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