libports: raise stack size of libc apps

Triggered by cc1plus in noux_tool_chain_auto on hw_arndale that caused
an overflow on its 64K stack.

Ref #1941

repos/libports/src/lib/libc/task.cc

@@ -47,6 +47,9 @@ struct Task_resume
 };
 
 
+Genode::size_t Component::stack_size() {
+	return 32UL * 1024 * sizeof(Genode::addr_t); }
+
 /**
  * Libc task
  *