libxx: Change CXX_LIBSUPCXX to LIBSUPCXX

align with other Kconfig(e.g. LIBCXXABI, LIBCXX, UCLIBCXX)

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>

libs/libxx/Kconfig

@@ -54,7 +54,7 @@ if LIBCXX || UCLIBCXX
 
 choice
 	prompt "C++ low level library select"
-	default CXX_LIBSUPCXX
+	default LIBSUPCXX
 
 config LIBCXXABI
 	bool "LLVM low level C++ Library"
@@ -63,7 +63,7 @@ config LIBCXXABI
 		https://libcxxabi.llvm.org/
 		Select if your use libc++abi as lower level c++ library
 
-config CXX_LIBSUPCXX
+config LIBSUPCXX
 	bool "GNU low level libsupc++"
 	---help---
 		Select if your toolchain provides libsupc++ and use libsupc++ as lower

libs/libxx/Makefile

@@ -21,7 +21,7 @@ include $(TOPDIR)/Make.defs
 
 CXXSRCS = libxx_cxa_atexit.cxx
 
-ifeq ($(CONFIG_CXX_LIBSUPCXX),y)
+ifeq ($(CONFIG_LIBSUPCXX),y)
 CXXSRCS += libxx_impure.cxx
 else
 CXXSRCS += libxx_eabi_atexit.cxx