util: Include stddef.h in util/macros.h

This is required for offsetof, used by the container_of macro.

Signed-off-by: Matt Coster <matt.coster@imgtec.com>
Reviewed-by: Chia-I Wu <olvaffe@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18368>

src/util/macros.h

@@ -24,9 +24,10 @@
 #ifndef UTIL_MACROS_H
 #define UTIL_MACROS_H
 
-#include <stdio.h>
 #include <assert.h>
+#include <stddef.h>
 #include <stdint.h>
+#include <stdio.h>
 
 /* Compute the size of an array */
 #ifndef ARRAY_SIZE