Revert AVX512 capability check from PR #1980 (moved to build)

getarch.c

@@ -94,14 +94,6 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <sys/sysinfo.h>
 #endif
 
-#if defined(__x86_64__) || defined(_M_X64)
-#if (( defined(__GNUC__)  && __GNUC__   > 6 && defined(__AVX2__)) || (defined(__clang__) && __clang_major__ >= 6))
-#else
-#ifndef NO_AVX512
-#define NO_AVX512
-#endif
-#endif
-#endif
 /* #define FORCE_P2		*/
 /* #define FORCE_KATMAI		*/
 /* #define FORCE_COPPERMINE	*/