Retire Piledriver/Steamroller/Excavator daxpy microkernels as well
Retire Piledriver/Steamroller/Excavator daxpy microkernels as well

related to issue #1332
xianyi/OpenBLAS,kortschak/OpenBLAS,kortschak/OpenBLAS,kortschak/OpenBLAS,kortschak/OpenBLAS,kortschak/OpenBLAS,kortschak/OpenBLAS,xianyi/OpenBLAS,kortschak/OpenBLAS,xianyi/OpenBLAS,kortschak/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,kortschak/OpenBLAS