Fix Visual Studio 12 build Error in sum_squares_2d

Some versions of Visual Studio don't have the
_mm256_set1_epi64x function. Using __m256i yy_set1_64_from_32i
instead.

BUG=aomedia:2138

Change-Id: Ifcdc804ca069c12e290328ba8b4326050d6234ee
diff --git a/aom_dsp/x86/sum_squares_avx2.c b/aom_dsp/x86/sum_squares_avx2.c
index 4c00b15..0af44e3 100644
--- a/aom_dsp/x86/sum_squares_avx2.c
+++ b/aom_dsp/x86/sum_squares_avx2.c
@@ -13,6 +13,7 @@
 #include <smmintrin.h>
 
 #include "aom_dsp/x86/synonyms.h"
+#include "aom_dsp/x86/synonyms_avx2.h"
 #include "aom_dsp/x86/sum_squares_sse2.h"
 #include "config/aom_dsp_rtcd.h"
 
@@ -20,7 +21,7 @@
                                                 int width, int height) {
   uint64_t result;
   __m256i v_acc_q = _mm256_setzero_si256();
-  const __m256i v_zext_mask_q = _mm256_set1_epi64x(0xffffffff);
+  const __m256i v_zext_mask_q = yy_set1_64_from_32i(0xffffffff);
   for (int col = 0; col < height; col += 4) {
     __m256i v_acc_d = _mm256_setzero_si256();
     for (int row = 0; row < width; row += 16) {