force the X to zero for DTCM since the dhrystone test have a uninitialized memory value as X
force the X to zero for DTCM since the dhrystone test have a uninitialized memory value as X

SI-RISCV/e200_opensource,SI-RISCV/e200_opensource,SI-RISCV/e200_opensource,SI-RISCV/e200_opensource,SI-RISCV/e200_opensource