added and tested optimized dgemv_n kernel for haswell

kernel/x86_64/KERNEL.HASWELL

@@ -1,7 +1,7 @@
 SGEMVNKERNEL = sgemv_n_4.c
 SGEMVTKERNEL = sgemv_t_4.c
 
-DGEMVNKERNEL = dgemv_n.c
+DGEMVNKERNEL = dgemv_n_4.c
 DGEMVTKERNEL = dgemv_t_4.c
 
 ZGEMVNKERNEL = zgemv_n.c

kernel/x86_64/dgemv_n_4.c

@@ -31,6 +31,8 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #if defined(NEHALEM)
 #include "dgemv_n_microk_nehalem-4.c"
+#elif defined(HASWELL)
+#include "dgemv_n_microk_haswell-4.c"
 #endif