mtd: move definitions to enlarge their range

Some helpers might be useful in a future 'mtd' U-Boot command to parse
MTD device list.
Signed-off-by: NMiquel Raynal <miquel.raynal@bootlin.com>

drivers/mtd/mtdcore.h

@@ -5,7 +5,6 @@
 
 extern struct mutex mtd_table_mutex;
 
-struct mtd_info *__mtd_next_device(int i);
 int add_mtd_device(struct mtd_info *mtd);
 int del_mtd_device(struct mtd_info *mtd);
 int add_mtd_partitions(struct mtd_info *, const struct mtd_partition *, int);
@@ -16,8 +15,3 @@ int parse_mtd_partitions(struct mtd_info *master, const char * const *types,
 
 int __init init_mtdchar(void);
 void __exit cleanup_mtdchar(void);
-
-#define mtd_for_each_device(mtd)			\
-	for ((mtd) = __mtd_next_device(0);		\
-	     (mtd) != NULL;				\
-	     (mtd) = __mtd_next_device(mtd->index + 1))

include/linux/mtd/mtd.h

@@ -533,6 +533,12 @@ int del_mtd_device(struct mtd_info *mtd);
 int add_mtd_partitions(struct mtd_info *, const struct mtd_partition *, int);
 int del_mtd_partitions(struct mtd_info *);
 
+struct mtd_info *__mtd_next_device(int i);
+#define mtd_for_each_device(mtd)			\
+	for ((mtd) = __mtd_next_device(0);		\
+	     (mtd) != NULL;				\
+	     (mtd) = __mtd_next_device(mtd->index + 1))
+
 int mtd_arg_off(const char *arg, int *idx, loff_t *off, loff_t *size,
 		loff_t *maxsize, int devtype, uint64_t chipsize);
 int mtd_arg_off_size(int argc, char *const argv[], int *idx, loff_t *off,