distro_info: fix get_arch for arm64 and armv7

bin/distro_info

@@ -475,8 +475,13 @@ case "$DIST_ARCH" in
     '9000/800')
         DIST_ARCH="parisc"
         ;;
-    armv*)
-        if [ -z "$(readelf -A /proc/self/exe | grep Tag_ABI_VFP_args)" ] ; then
+    'arm64' | 'aarch64')
+        DIST_ARCH='aarch64'
+        ;;
+    armv7*)
+        # TODO: use uname only
+        # uses binutils package
+        if which readelf >/dev/null 2>/dev/null && [ -z "$(readelf -A /proc/self/exe | grep Tag_ABI_VFP_args)" ] ; then
             DIST_ARCH="armel"
         else
             DIST_ARCH="armhf"