Workaround for stray 'free' macro
Related to littlevgl/lv_binding_micropython#11 'Build error for STM32 port due to 'free()' macro'
* DEFINES
*********************/
+/* "free" is used as a function pointer (in lv_fs_drv_t).
+ * We must make sure "free" was not defined to a platform specific
+ * free function, otherwise compilation would fail.
+ */
+#ifdef free
+#undef free
+#endif
+
/**********************
* TYPEDEFS
**********************/
