add missing config symbol in x86_64 configuration

SVN-Revision: 14132

toolchain/uClibc/config/0.9.30/x86_64

@@ -212,6 +212,7 @@ UCLIBC_BUILD_NOEXECSTACK=y
 CROSS_COMPILER_PREFIX=""
 UCLIBC_EXTRA_CFLAGS=""
 # DODEBUG is not set
+# DODEBUG_PT is not set
 DOSTRIP=y
 # DOASSERTS is not set
 # SUPPORT_LD_DEBUG is not set