Merge pull request #3130 from martin-frbg/issue3128

Replace spurious AVX512 requirement in the Haswell srot microkernel with an AVX2/FMA3 guard

kernel/x86_64/srot_microk_haswell-2.c

@@ -1,5 +1,4 @@
-/* need a new enough GCC for avx512 support */
-#if (( defined(__GNUC__)  && __GNUC__   > 6 && defined(__AVX512CD__)) || (defined(__clang__) && __clang_major__ >= 9))
+#if defined(HAVE_FMA3)  && defined(HAVE_AVX2)
 
 #define HAVE_SROT_KERNEL 1