loongarch64: Add optimizations for axpy and axpby.

Author: yancheng

kernel/loongarch64/KERNEL.LOONGSON2K1000

@@ -37,4 +37,10 @@ DCOPYKERNEL =  dcopy_lsx.S
 SSWAPKERNEL =  sswap_lsx.S
 DSWAPKERNEL =  dswap_lsx.S
 
+SAXPYKERNEL =  saxpy_lsx.S
+DAXPYKERNEL =  daxpy_lsx.S
+
+SAXPBYKERNEL = saxpby_lsx.S
+DAXPBYKERNEL = daxpby_lsx.S
+
 endif

kernel/loongarch64/KERNEL.LOONGSON3R5

@@ -37,6 +37,12 @@ DCOPYKERNEL =  dcopy_lasx.S
 SSWAPKERNEL =  sswap_lasx.S
 DSWAPKERNEL =  dswap_lasx.S
 
+SAXPYKERNEL =  saxpy_lasx.S
+DAXPYKERNEL =  daxpy_lasx.S
+
+SAXPBYKERNEL = saxpby_lasx.S
+DAXPBYKERNEL = daxpby_lasx.S
+
 DGEMMKERNEL    = dgemm_kernel_16x4.S
 DGEMMINCOPY    = dgemm_ncopy_16.S
 DGEMMITCOPY    = dgemm_tcopy_16.S