Use sgemm_ncopy_4_skylakex.c also for Haswell

sgemm_ncopy_4_skylakex.c uses SSE transpose operations where the
real perf win happens; this also works great for Haswell.

This gives double digit percentage gains on small and skinny matrices

kernel/x86_64/KERNEL.HASWELL

@@ -36,7 +36,7 @@ SGEMMKERNEL    =  sgemm_kernel_16x4_haswell.S
 SGEMM_BETA     =  sgemm_beta_skylakex.c
 SGEMMINCOPY    =  ../generic/gemm_ncopy_16.c
 SGEMMITCOPY    =  ../generic/gemm_tcopy_16.c
-SGEMMONCOPY    =  ../generic/gemm_ncopy_4.c
+SGEMMONCOPY    =  sgemm_ncopy_4_skylakex.c
 SGEMMOTCOPY    =  ../generic/gemm_tcopy_4.c
 SGEMMINCOPYOBJ =  sgemm_incopy$(TSUFFIX).$(SUFFIX)
 SGEMMITCOPYOBJ =  sgemm_itcopy$(TSUFFIX).$(SUFFIX)

kernel/x86_64/sgemm_ncopy_4_skylakex.c

@@ -49,8 +49,7 @@ int CNAME(BLASLONG m, BLASLONG n, FLOAT * __restrict a, BLASLONG lda, FLOAT * __
   FLOAT *b_offset;
   FLOAT  ctemp1,  ctemp2,  ctemp3,  ctemp4;
   FLOAT  ctemp5,  ctemp6,  ctemp7,  ctemp8;
-  FLOAT  ctemp9, ctemp10, ctemp11, ctemp12;
-  FLOAT ctemp13, ctemp14, ctemp15, ctemp16;
+  FLOAT  ctemp9,  ctemp13;
 
   a_offset = a;
   b_offset = b;