Detect NEON and VFPv4 on armv7

--- src/zimg/common/arm/cpuinfo_arm.cpp.orig	2020-08-23 13:47:57 UTC
+++ src/zimg/common/arm/cpuinfo_arm.cpp
@@ -8,6 +8,19 @@
 #elif defined(__linux__)
   #include <sys/auxv.h>
   #include <asm/hwcap.h>
+#elif defined(__FreeBSD__)
+  #include <sys/auxv.h>
+  static unsigned long getauxval(unsigned long type)
+  {
+      /* Only AT_HWCAP* return unsigned long */
+      if (type != AT_HWCAP && type != AT_HWCAP2) {
+	  return 0;
+      }
+
+      unsigned long ret = 0;
+      elf_aux_info(type, &ret, sizeof(ret));
+      return ret;
+  }
 #endif
 
 #include "cpuinfo_arm.h"
@@ -28,7 +41,7 @@ ARMCapabilities do_query_arm_capabilities() noexcept
 #elif defined(_WIN32)
 	caps.neon  = IsProcessorFeaturePresent(PF_ARM_NEON_INSTRUCTIONS_AVAILABLE);
 	caps.vfpv4 = IsProcessorFeaturePresent(PF_ARM_FMAC_INSTRUCTIONS_AVAILABLE);
-#elif defined(__linux__)
+#elif defined(__linux__) || defined(__FreeBSD__)
 	long hwcaps = getauxval(AT_HWCAP);
 	caps.neon  = !!(hwcaps & HWCAP_NEON);
 	caps.vfpv4 = !!(hwcaps & HWCAP_VFPv4);