[components/dfs/ramfs] Automatically select memheap when ramfs enabled.|当使能ramfs时自动选中memheap。

components/dfs/Kconfig

@@ -113,6 +113,7 @@ if RT_USING_DFS
 
     config RT_USING_DFS_RAMFS
         bool "Enable RAM file system"
+        select RT_USING_MEMHEAP
         default n
 
     config RT_USING_DFS_UFFS