configure: openCl does not build on 10.6 mac default no in that case

Change-Id: I84b74cb9e9893996179b4b0229853903e29fe28d

configure.ac

@@ -9995,13 +9995,17 @@ OPENCL_LIBS=
 OPENCL_CFLAGS=
 ENABLE_OPENCL=
 AC_MSG_CHECKING([OpenCL])
-if test \( -z "$with_opencl_sdk" -o "$with_opencl_sdk" = yes \) -a $_os = Darwin; then
+if test \( -z "$with_opencl_sdk" -o "$with_opencl_sdk" = yes \) -a $_os = Darwin ; then
     # OS X
+    if test "$with_open_sdk" = yes -o "$with_macosx_sdk" != "10.6" ; then
         AC_MSG_RESULT([yes, always on OS X])
         ENABLE_OPENCL=TRUE
         OPENCL_CFLAGS=
         OPENCL_LIBS="-framework OpenCL"
         AC_DEFINE(HAVE_FEATURE_OPENCL)
+    else
+        AC_MSG_RESULT([no])
+    fi
 elif test -z "$with_opencl_sdk" -o "$with_opencl_sdk" = no; then
     AC_MSG_RESULT([no])
 else