RISCV: config: Remove CFG_SYS_SDRAM_BASE

Remove CFG_SYS_SDRAM_BASE so that we can get DRAM base
from dt instead of compile time config.
Removing this config helps the u-boot more portable.

Signed-off-by: Jimmy Ho <jimmy.ho@sifive.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
2 files changed