riscv64: enable CTORS, fixes C++ applications, found by sorear

extra/Configs/Config.in

@@ -544,7 +544,7 @@ config LDSO_LD_LIBRARY_PATH
 
 config UCLIBC_CTOR_DTOR
 	bool
-	default y if !TARGET_riscv64 && !TARGET_lm32
+	default y
 	help
 	  If you wish to build uClibc with support for global constructor
 	  (ctor) and global destructor (dtor) support, then answer Y here.