Add low level platform initialization for the AST2600 SoC.
The 2-stage booting with U-Boot SPL are leveraged to support
different booting mode.
However, currently the patch supports only the booting from
memory-mapped SPI flash.
Signed-off-by: Chia-Wei, Wang <chiawei_wang@aspeedtech.com>
Reviewed-by: Ryan Chen <ryan_chen@aspeedtech.com>
The hardcoded platform variables such as DRAM base address are not
common to Aspeed SoCs AST24xx/AST25xx/AST26xx. This patch replaces
those hardcoded with macros defined in a newly added header, where
the basic SoC HW information are assigned accordingly.
Signed-off-by: Chia-Wei, Wang <chiawei_wang@aspeedtech.com>