Hi,
Can you please make this changes in board def file at u-boot source.
I assume that you are using da850evm.h board definition file.
Ex:
include/configs/da850evm.h
#define CONFIG_SYS_DA850_DDR2_DDRPHYCR (DV_DDR_PHY_PWRDNEN | \
DV_DDR_PHY_EXT_STRBEN | \
(0x4 << DV_DDR_PHY_RD_LATENCY_SHIFT))