Use dedicated option for 128-bit long double.

samples/powerpc-e500v2-linux-gnuspe/crosstool.config

@@ -10,9 +10,10 @@ CT_TARGET_VENDOR="e500v2"
 CT_KERNEL_linux=y
 CT_BINUTILS_EXTRA_CONFIG_ARRAY="--enable-spe=yes --enable-e500x2 --with-e500x2"
 CT_CC_GCC_SHOW_LINARO=y
-CT_CC_GCC_CORE_EXTRA_CONFIG_ARRAY="--with-long-double-128 --enable-e500_double"
-CT_CC_GCC_EXTRA_CONFIG_ARRAY="--with-long-double-128 --enable-e500_double"
+CT_CC_GCC_CORE_EXTRA_CONFIG_ARRAY="--enable-e500_double"
+CT_CC_GCC_EXTRA_CONFIG_ARRAY="--enable-e500_double"
 # CT_CC_GCC_ENABLE_TARGET_OPTSPACE is not set
+CT_CC_GCC_LDBL_128=y
 CT_CC_LANG_CXX=y
 CT_DEBUG_gdb=y
 # CT_GDB_CROSS_PYTHON is not set