OneNAND: Remove unused read_spareram

Remove unused read_spareram and add unlock_all as kernel does

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
diff --git a/include/linux/mtd/onenand.h b/include/linux/mtd/onenand.h
index 2597e34..06f7baf 100644
--- a/include/linux/mtd/onenand.h
+++ b/include/linux/mtd/onenand.h
@@ -83,10 +83,9 @@
 			size_t len);
 	int (*wait) (struct mtd_info *mtd, int state);
 	int (*bbt_wait) (struct mtd_info *mtd, int state);
+	void (*unlock_all)(struct mtd_info *mtd);
 	int (*read_bufferram) (struct mtd_info *mtd, loff_t addr, int area,
 			       unsigned char *buffer, int offset, size_t count);
-	int (*read_spareram) (struct mtd_info *mtd, loff_t addr, int area,
-			       unsigned char *buffer, int offset, size_t count);
 	int (*write_bufferram) (struct mtd_info *mtd, loff_t addr, int area,
 				const unsigned char *buffer, int offset,
 				size_t count);