HAL_ChibiOS: deprecate realloc for ChibiOS build, so as to return error when used

libraries/AP_HAL_ChibiOS/hwdef/common/stdio.h

@@ -44,9 +44,10 @@ int printf(const char *fmt, ...);
 void *malloc(size_t size);
 void *calloc(size_t nmemb, size_t size);
 void free(void *ptr);
-
+void *realloc(void* ptr, size_t size) __attribute__((deprecated));
 extern int (*vprintf_console_hook)(const char *fmt, va_list arg);
 
+
 #define L_tmpnam 32
 
 #ifdef __cplusplus