bsp: cvitek/c906B: feat: add config of bootfs

To support more choice on bootfs. romfs, cromfs are now supported on
risc_v_big platform.

Changes:
- added mount operations under port
- added prototypes for cromfs init APIs

Signed-off-by: Shell <smokewood@qq.com>
Reviewed-on: https://github.com/RT-Thread/rt-thread/pull/9229
Reviewed-by: Chen Wang <unicorn_wang@outlook.com>

components/dfs/dfs_v2/filesystems/cromfs/dfs_cromfs.h

@@ -11,6 +11,9 @@
 #ifndef  __DFS_CROMFS_H__
 #define  __DFS_CROMFS_H__
 
+#include <stdint.h>
+
 int dfs_cromfs_init(void);
+uint8_t *cromfs_get_partition_data(uint32_t *len);
 
 #endif  /*__DFS_CROMFS_H__*/