dm: drop unused helper in MTD header

include/mtd.h might be included by files even if CONFIG_DM is not
enabled. In this case, the call to dev_get_uclass_priv() would trigger
a build error. Because this helper has no user, let's drop it off.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>

include/mtd.h

@@ -8,15 +8,4 @@
 
 #include <linux/mtd/mtd.h>
 
-/*
- * Get mtd_info structure of the dev, which is stored as uclass private.
- *
- * @dev: The MTD device
- * @return: pointer to mtd_info, NULL on error
- */
-static inline struct mtd_info *mtd_get_info(struct udevice *dev)
-{
-	return dev_get_uclass_priv(dev);
-}
-
 #endif	/* _MTD_H_ */