Add SDRAM driver for Agilex SoC. Signed-off-by: Tien Fong Chee <tien.fong.chee@intel.com> Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com> Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>