py/mphal.h: Add stddef.h for size_t.

yf13 · yf13 · commit d5095b545a4d · 2025-07-29T18:12:31.000+08:00
This includes `&lt;stddef.h&gt;` for size_t.

Signed-off-by: Yanfeng Liu &lt;yfliu2008@qq.com&gt;
diff --git a/py/mphal.h b/py/mphal.h
@@ -27,6 +27,7 @@
 #define MICROPY_INCLUDED_PY_MPHAL_H
 
 #include <stdint.h>
+#include <stddef.h>
 #include "py/mpconfig.h"
 
 #ifdef MICROPY_MPHALPORT_H
