[atomic]修复bsp/simulator vs2019编译下 atomic 两个volatile的问题 (#7736)

include/rtdef.h

@@ -132,7 +132,7 @@ typedef rt_base_t                       rt_off_t;       /**< Type for offset */
     #include <stdatomic.h>
     typedef atomic_size_t rt_atomic_t;
 #elif defined(RT_USING_HW_ATOMIC)
-    typedef volatile rt_base_t rt_atomic_t;
+    typedef rt_base_t rt_atomic_t;
 #else
 
     /* To detect std atomic */
@@ -140,7 +140,7 @@ typedef rt_base_t                       rt_off_t;       /**< Type for offset */
         #include <stdatomic.h>
         typedef atomic_size_t rt_atomic_t;
     #else
-        typedef volatile rt_base_t rt_atomic_t;
+        typedef rt_base_t rt_atomic_t;
     #endif /* __GNUC__ && !__STDC_NO_ATOMICS__ */
 
 #endif /* RT_USING_STDC_ATOMIC */