Make sure to use the arm version of dynamic.c in ARM64 DYNAMIC_ARCH
Make sure to use the arm version of dynamic.c in ARM64 DYNAMIC_ARCH

cf. #1908
xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS